The effects of posterior cruciate ligament rupture on the biomechanical and histological characteristics of the medial collateral ligament: an animal study.

BACKGROUND: To investigate the effect of complete rupture of the posterior cruciate ligament (PCL) on the biomechanics and histology of the medial collateral ligament (MCL). MATERIALS AND METHODS: Seventy-two male rabbits were randomly divided into two groups: the ruptured group was treated with complete PCL amputation, while the intact group was only subjected to PCL exposure without amputation. Eighteen rabbits were randomly sacrificed at 8, 16, 24, and 40 weeks after the operation, and their specimens were processed for mechanical tensile testing, nano-indentation experiments, hematoxylin-eosin (HE) staining, and picrosirius-polarization staining. RESULTS: There was no significant difference in the length and maximum displacement of the MCL between the ruptured group and the intact group at each time point. The maximum load of the ruptured group was significantly smaller than that of the intact group at 40 W. The elastic modulus and micro-hardness of the ruptured group increased significantly at 24 W and decreased significantly at 40 W. At 16 W and 24 W after PCL rupture, the number of type I collagen fibers and type III collagen fibers in the MCL of the ruptured group was significantly increased compared with that of the intact group. While the type I collagen fibers of the ruptured group were significantly decreased compared with the intact group at 40 W, there was no significant difference in type III collagen fibers between the ruptured group and the intact group. CONCLUSION: PCL rupture has no significant effect on the mechanical and histological properties of MCL in a short period of time under physiological loading, but the histological and mechanical properties of MCL decrease with time.

Arthroscopic pie-crusting release of the posteromedial complex of the knee for surgical treatment of medial meniscus injury.

BACKGROUND: An arthroscopic narrow posteromedial gap of the knee may cause failure of a meniscus operation. The posteromedial complex (PMC) of the knee, including the posterior part of the medial collateral ligament (MCL) and the posterior oblique ligament (POL), has a restrictive effect on the opening of the posteromedial gap of the knee in the half-extension position. Thus, we evaluated the radiological and clinical results of pie-crusting release of the PMC for arthroscopic meniscal surgery in tight knees. METHODS: Sixty patients with posterior injury of the medial meniscus were reviewed. All patients accepted arthroscopic pie-crusting release of the PMC. Fourty patients accepted meniscoplasty, and 20 patients accepted meniscal suturing. To evaluate the arthroscopic opening of the medial gap in 20° half-extension under 11-kg valgus stress, the width of the medial space before and after release were measured. During follow-up, the medial stability was evaluated by radiographic measurements of the joint space width (JSW) in 20° half-extension. Magnetic resonance imaging (MRI) was conducted to evaluate healing of the MCL and meniscus. Knee functions were evaluated using VAS (visual analogy score), Lysholm, IKDC (International Knee Documentation Committee) and Tegner scoring systems. RESULTS: In all patients, meniscus operations were performed without iatrogenic cartilage injury. After PMC release, the arthroscopic width of the medial space was 5.7 ± 0.5 mm, larger than that before release (2.5 ± 0.5 mm, p < 0.01). The follow-up time was 21.93 ± 7.04 months, there was no residual valgus laxity of the knee. The radiographic JSW was 5.97 ± 0.8 mm preoperatively, 9.2 ± 1.1 mm in the 1st week postoperatively, and 6.1 ± 0.9 mm by the 3rd postoperative month, showing no differences between preoperative and 3 months postoperative measurement (p > 0.05). For sutured meniscus, MRI showed healing in 15 patients while five had two-grade abnormal signals. VAS, Lysholm, IKDC and Tegner scores were 1.80 ± 0.51, 80.08 ± 3.74, 82.17 ± 4.64 and 5.48 ± 0.59, respectively, showing significant differences compared with the preoperative scores (5.57 ± 0.69, 48.17 ± 4.22, 51.42 ± 4.02 and 3.20 ± 0.68, respectively, p< 0.01). CONCLUSIONS: Pie-crusting release of the PMC can increase the posteromedial space and improve the visual field of the knee under arthroscopy, while neither causing no residual valgus instability of the knee nor affecting the clinical outcome at the final follow-up.

Valgus stress radiography following superficial medial collateral ligament reconstruction using a modified LaPrade technique with adjustable loop femoral fixation.

Purpose of this study was to assess postoperative laxity of MCL reconstructions utilizing a modified LaPrade superficial MCL reconstruction. We retrospectively reviewed post-operative valgus stress radiographs in 23 multiligament injured patients who underwent concurrent sMCL and cruciate ligament reconstruction by a single surgeon. Post- operatively, 23 patients underwent valgus stress radiographs that were assessed at a mean of 8.7 months (range: 4-13 months), and mean SSD was 0.64mm ± 0.42mm. Eight patients underwent both pre- and post-operative valgus stress radiographs. Post-operative (0.09mm ± 0.63mm) SSD was found to be significantly reduced compared to pre-operative (2.07mm ± 0.44mm) SSD (mean diff. = 1.98mm, 95% CI = 0.72-3.24, P=0.007). Inter-observer reliability value for medial compartment gap measurement was 0.91 with a 95% confidence interval of 0.34- 0.97. In conclusion, presented technique results in excellent static stability of the knee as measured by valgus stress radiography at a minimum of 6 months postoperative. Level of Evidence: IV.

Treatment of a calcific bursitis of the medial collateral ligament: a rare cause of painful knee.

Medial knee pain is common in clinical practice and can be caused by various conditions. In rare cases, it can even be by calcific bursitis of the medial collateral ligament (MCL). Treatment of calcific bursitis and/or calcification of the MCL classically includes observation, local injections, shockwave therapy and surgical resection. We report a case of nontraumatic medial knee pain poorly responsive to conservative treatments. Ultrasound (US) imaging revealed a massive lobed hyperechoic formation with partial acoustic shadow in the MCL context compatible with calcific bursitis, and magnetic resonance imaging (MRI) confirmed the presence of the bursa's calcific deposit surrounded by hyperintense signal compatible with pericalcific edema. We performed a double-needle ultrasound-guided percutaneous lavage (UGPL), which is today a fairly common treatment for many musculoskeletal disorders, such as rotator cuff calcific tendinopathy and elbow extensor tendons pathology, but regarding the knee, it is not part of ordinary care. This report shows the clinical and imaging presentation of calcific bursitis of the MCL and describes in detail the technique to perform the UGPL with a system of two needles, two syringes and a double connection to ensure a correct lavage of the calcium deposit without significant intrabursal pressure increase and consequently without pain during the procedure.

Comparation and evaluation of the accuracy of the sulcus localization method to establish the medial patellofemoral ligament femoral tunnel: a cadaveric and clinical study.

BACKGROUND: In anatomic medial patellofemoral ligament (MPFL) reconstruction, malpositioning of the MPFL femoral tunnel is common. A palpable sulcus reportedly exists at the anatomic femoral attachment of the MPFL. The present study aimed to investigate the accuracy of the sulcus localization method to establish the MPFL femoral tunnel. METHODS: A cadaveric study was first done on 12 knees to evaluate the accuracy of the sulcus localization method to establish the entry points of the MPFL femoral tunnel in comparison with the midpoint and fluoroscopic localization methods. The center of the native MPFL femoral attachment was served as the reference in the cadaveric study. A clinical study was then performed to further evaluate the accuracy of the sulcus localization method in 53 patients (60 knees). Schöttle's point was served as the reference in the clinical study. Femoral tunnel placement was defined as accurate when it was less than 5 mm from Schöttle's point. In both the cadaveric and clinical studies, MPFL femoral tunnel placement was assessed on postoperative reconstructed three-dimensional computed tomography images. In the cadaveric study, the accuracy of different localization methods was compared using analysis of variance. RESULTS: In the cadaveric study, the mean distances from the native MPFL attachment to the femoral tunnel entry point were 4.2 ± 1.0 mm (range 2.4-5.6 mm), 4.4 ± 1.4 mm (range 1.8-6.6 mm) and 2.9 ± 0.8 mm (range 1.9-4.4 mm) using the midpoint, fluoroscopic, and sulcus localization methods, respectively; this distance significantly differed between the midpoint and sulcus localization methods, and between the fluoroscopic and sulcus localization methods (p ≤ .05). While there were no significant differences between the midpoint and fluoroscopic localization methods (n.s.). In the clinical study, the mean distance between the femoral tunnel and Schöttle's point was 3.5 ± 1.5 mm (range 0.4-6.1 mm), with accurate tunnel placement achieved in 49 of 60 cases (82%). CONCLUSION: The sulcus localization method can accurately guide MPFL femoral tunnel placement. This method might be useful for orthopedic surgeons. LEVEL OF EVIDENCE: IV.

Accuracy of internet images of ligamentous knee injuries.

BACKGROUND: The internet is an easily accessible resource for both providers and patients. Despite this, the internet is not peer reviewed, leaving searches subject to inaccuracies, especially with regards to medical information. The purpose of this study was to review internet images of anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), and lateral collateral ligament (LCL) tears using two popular search engines: Google and Bing. METHODS: A search query was performed on both Google and Bing for the following terms: 'ACL tear', 'PCL tear', 'MCL tear' and 'LCL tear'. The first 100 images of each individual search were analyzed by three independent orthopedists. RESULTS: The inter-rater reliability was very good for PCL tear on Bing (Cronbach's alpha = 0.89) and excellent (Cronbach's alpha > 0.9) for the remainder of the search queries. When comparing Google to Bing, the only significant difference occurred in the ACL group, with Bing returning a significantly greater number of correct images 60%, 95% CI: 53.2 - 66.7%) compared to Google (45% correct, 95% CI: 38.1-51.8%), p = 0.034. With regards to the other ligaments Bing was more accurate than Google for PCL (39% versus 38%), and LCL (32% to 30%). Both sites were 48% accurate for MCL tear. CONCLUSION: Ultimately, our study revealed that physicians should take an active role in making high quality, easy to understand medical resources and anatomic diagrams available to their patients to avoid confusion and enhance understanding when querying the internet for additional information regarding their condition.

Objective quantification of ligament balancing using VERASENSE in measured resection and modified gap balance total knee arthroplasty.

BACKGROUND: Soft tissue balancing which is above all most important factor of total knee arthroplasty, has been performed by subjective methods. Recently objective orthosensor has been developed for compartment pressure measurement. The purpose of this study was: (1) to quantify the compartment pressure of the joint throughout the range of motion during TKA using orthosensor, (2) to determine the usefulness of orthosensor by analyzing correlation between the pressure in both compartment with initial trial and after final implantation, and (3) to evaluate the types and effectiveness of additional ligament balancing procedures to compartment pressure. METHODS: Eighty-four patients underwent total knee arthroplasty (TKA) using VERASENSE Knee System. TKA was performed by measured resection and modified gap balance technique. Compartment pressure was recorded on full extension, 30°, 60°, 90° and full flexion at initial (INI), after each additional procedure, and after final (FIN) implantation. "Balanced" knees were defined as when the compartment pressure difference was less than 15 pounds. RESULTS: Thirty patients (35.7%) showed balanced knee initially and 79 patients (94.0%) showed balance after final implantation. The proportion of balanced knee after initial bony resection, modified gap balancing TKAs showed significantly higher proportion than measured resection TKAs (P = 0.004) On both compartment, the pressure was generally decreased throughout the range of motion. Linear correlation on both compartment showed statistically significant throughout the range on motion, with higher correlation value on the lateral compartment. Total 66 additional ligament balancing procedures were performed. CONCLUSION: Using orthosensor, we could obtain 94% quantified balance knee, consequently. And between the techniques, measured resection TKA showed less balanced knee and also required more additional procedures compared to modified gap balancing TKA. Furthermore, with the acquired quantified data during appropriate ligament balancing, the surgeon could eventually reduce the complications associated with soft tissue imbalance in the future.

Microparticles Locally Deliver Active Interleukin-1 Receptor Antagonist In Vivo.

Despite significant research in therapeutic protein delivery, localized and sustained delivery of active therapeutic proteins remains a challenge. Delivery is a particular challenge for therapeutic proteins with a short half-life. Herein, localized delivery of interleukin-1 receptor antagonist (IL-1Ra) by mineral coated microparticles (MPs) is assessed in a healing rat medial collateral ligament (MCL). The local tissue concentration and systemic serum concentration of IL-1Ra, the anti-inflammatory activity of IL-1Ra delivered with MPs, and whether IL-1Ra loaded MPs (IL-1Ra MPs) are immunogenic in a healing ligament are also examined. IL-1Ra MPs significantly increase the local concentration of IL-1Ra compared to soluble IL-1Ra at 7 and 14 days after treatment but do not elevate the systemic concentration of IL-1Ra at these time points, indicating localized delivery of IL-1Ra. IL-1Ra MPs significantly reduce inflammation caused by the MPs themselves, indicating the IL-1Ra is active. Finally, IL-1Ra MPs do not induce a foreign body response and decrease the immunogenicity of human IL-1Ra in a healing rat MCL. Overall, mineral coated microparticles have the ability to locally deliver active therapeutic proteins for an extended period of time.

A biomechanical analysis of triangular medial knee reconstruction.

BACKGROUND: The purpose of this study was to evaluate and compare knee kinematics and stability following either triangular or anatomical reconstruction of the superficial medial collateral ligament (sMCL) and posterior oblique ligament (POL). METHODS: In a cadaveric model (12 knees), the stability and kinematics following two experimental sMCL and POL reconstructions were compared in sMCL- and POL-deficient knees versus normal knees. The first reconstruction was a triangular reconstruction of the sMCL and POL, while the second involved an anatomical reconstruction of the sMCL and POL. All knees were tested through four different states. The changes in valgus angles, external rotation, and internal rotation were measured in the normal and sMCL- and POL-deficient knees, as well as in the knees that had undergone the two different forms (triangular and anatomical) of reconstruction. RESULTS: After initial sectioning of the sMCL and POL, we observed significantly increased valgus rotation, external rotation, and internal rotation at all knee flexion angles (0°, 20°, 30°, 60°, 90°). Additionally, passive stability testing demonstrated a significant increase in tibial internal rotation following triangular reconstruction compared with anatomical reconstruction at knee flexion angles of 20° and 30°. A significant increase in internal rotation was present following triangular reconstruction compared with anatomical reconstruction at 20° (mean difference = 2.77) (P = 0.008) and 30° (mean difference = 0.99) (P < 0.001) of knee flexion. CONCLUSION: This study suggests that anatomical sMCL and POL reconstruction produces slightly better biomechanical stability than triangular reconstruction. However, triangular reconstruction may restore a near-normal knee joint is both less invasive and more practical.

Medial collateral ligament bursitis in a patient with knee osteoarthritis.

BACKGROUND: Medial collateral ligament (MCL) bursitis has been described as a distended and inflamed bursa between the superficial and deep portions of the MCL. It is a rare but important cause of medial knee pain. CASE DESCRIPTION: A 65-year-old woman with knee osteoarthritis (OA) presented with severe pain and swelling in her left knee. She did not have a traumatic injury. After a clinical examination, a slight decrease in the range of motion of the left knee, and a painful swelling and tenderness over the medial side of the knee and proximal tibia were detected. The pain was exacerbated by valgus stress test. The magnetic resonance (MR) imaging showed a distended bursa with internal septations beneath the superficial portion of the MCL. MCL bursitis was considered as diagnosis and an ultrasound-guided corticosteroid injection into the bursa was performed. RESULTS: There was a significant improvement in pain intensity in the follow-up examination. A repeated MR imaging 2 months later showed a marked improvement, and approximation of the deep and superficial portions of the MCL. CONCLUSIONS: MCL bursitis, which is a rare condition, must be considered for the differential diagnosis of increased medial knee pain in patients with knee OA. Corticosteroid injection is an effective and safe treatment modality for the management.

An anatomical study of the origin, structure and insertion of the medial patellofemoral ligament.

BACKGROUND: Repair and reconstruction of the medial patellofemoral ligament (MPFL) has been undertaken for the treatment of patellar instability. For successful surgery detailed knowledge of the anatomy of the ligament is required. The aim of this study was to describe the origin, structure and insertion of the MPFL. MATERIALS AND METHODS: We studied cadaveric knees from 30 Chinese adults. We studied the origin, course and insertion of the MPFL. RESULTS: We found that the MPFL was composed of two main strands, superficial and deep. We also found that the insertion of the MPFL into the femur had three common patterns. All three were located between the adductor tubercle and the proximal part of superficial medial collateral ligament. CONCLUSIONS: We have added to the anatomical knowledge of the structure of the MPFL. Our study has implications for guiding bone tunnel positioning during MPFL reconstruction surgery. (Folia Morphol 2018; 77, 2: 356-361).

Raising the Joint Line in TKA is Associated With Mid-flexion Laxity: A Study in Cadaver Knees.

BACKGROUND: In a typical osteoarthritic knee with varus deformity, distal femoral resection based off the worn medial femoral condyle may result in an elevated joint line. In a setting of fixed flexion contracture, the surgeon may choose to resect additional distal femur to obtain extension, thus purposefully raising the joint line. However, the biomechanical effect of raising the joint line is not well recognized. QUESTIONS/PURPOSES: (1) What is the effect of the level of the medial joint line (restored versus raised) on coronal plane stability of a TKA? (2) Does coronal alignment technique (mechanical axis versus kinematic technique) affect coronal plane stability of the knee? (3) Can the effect of medial joint-line elevation on coronal plane laxity be predicted by an analytical model? METHODS: A TKA prosthesis was implanted in 10 fresh frozen nonarthritic cadaveric knees with restoration of the medial joint line at its original level (TKA0). Coronal plane stability was measured at 0°, 30°, 60°, 90°, and 120° flexion using a navigation system while applying an instrumented 9.8-Nm varus and valgus force moment. The joint line then was raised in two steps by recutting the distal and posterior femur by an extra 2 mm (TKA2) and 4 mm (TKA4), downsizing the femoral component and, respectively, adding a 2- and a 4-mm thicker insert. This was done with meticulous protection of the ligaments to avoid damage. Second, a simplified two-dimensional analytical model of the superficial medial collateral ligament (MCL) length based on a single flexion-extension axis was developed. The effect of raising the joint line on the length of the superficial MCL was simulated. RESULTS: Despite that at 0° (2.2° ± 1.5° versus 2.3° ± 1.1° versus 2.5° ± 1.1°; p = 0.85) and 90° (7.5° ± 1.9° versus 9.0° ± 3.1° versus 9.0° ± 3.5°; p = 0.66), there was no difference in coronal plane laxity between the TKA0, TKA2, and TKA4 positions, increased laxity at 30° (4.8° ± 1.9° versus 7.9° ± 2.3° versus 10.2° ± 2.0°; p < 0.001) and 60° (5.7° ± 2.7° versus 8.8° ± 2.9° versus 11.3° ± 2.9°; p < 0.001) was observed when the medial joint line was raised 2 and 4 mm. At 30°, this corresponds to an average increase of 64% (3.1°; p < 0.01) in mid-flexion laxity with a 2-mm raised joint line and a 111% (5.4°; p < 0.01) increase with a 4-mm raised joint line compared with the 9-mm baseline resection. No differences in coronal alignment were found between the knees implanted with kinematic alignment versus mechanical alignment at any flexion angle. The analytical model was consistent with the cadaveric findings and showed lengthening of the superficial MCL in mid-flexion. CONCLUSIONS: Despite a well-balanced knee in full extension and at 90° flexion, increased mid-flexion laxity in the coronal plane was evident in the specimens where the joint line was raised. CLINICAL RELEVANCE: When recutting the distal and posterior femur and downsizing the femoral component, surgeons should be aware that this action might increase the laxity in mid-flexion, even if the knee is stable at 0° and 90°.

Effectiveness and Safety of Needle Medial Collateral Ligament Pie-Crusting in Total Knee Arthroplasty: A Cadaveric Study.

Medial collateral ligament (MCL) pie-crusting technique in total knee arthroplasty (TKA) is one of the methods of medial release. The effects and risks of blade pie-crusting have been reported in previous studies. However, only a few have reported the safety and efficacy of needle pie-crusting. In this cadaveric study, we quantitatively evaluated the amount of gap change by MCL needle pie-crusting. We investigated five knees of four fresh human cadavers and performed posterior-stabilized TKA. Only deep MCL release as the medial release was conducted. We punctured the MCL from the deep layer to the superficial layer using a 18 G needle in a 90-degree flexion position for 0, 10, 20, 50, 75, and 100 times. Medial and lateral gaps were measured accurately with a balancer at determined times in 0 and 90-degree flexion positions. Changes in medial and lateral gaps were not significant differences in flexion and extension position. However, in 90-degree flexion, medial gap changes were tended to be larger than lateral gap changes. A 0.6 mm additional medial release and a 0.2 mm additional lateral release were found per 10 times pie crust in flexion position (100 times, p: 0.08). However, large differences existed among the cases. Needle pie-crusting is safer than blade pie-crusting because of the small efficacy of one-time pie crust. MCL needle pie-crusting showed varied effects for each case. This result indicates the risk of relaxation of an unexpected gap. Caution should be taken when choosing between needle pie-crusting and blade pie-crusting.

The Posteromedial Corner of the Knee: Anatomy, Pathology, and Management Strategies.

The posteromedial corner of the knee encompasses five medial structures posterior to the medial collateral ligament. With modern MRI systems, these structures are readily identified and can be appreciated in the context of multiligamentous knee injuries. It is recognized that anteromedial rotatory instability results from an injury that involves both the medial collateral ligament and the posterior oblique ligament. Like posterolateral corner injuries, untreated or concurrent posteromedial corner injuries resulting in rotatory instability place additional strain on anterior and posterior cruciate ligament reconstructions, which can ultimately contribute to graft failure and poor clinical outcomes. Various options exist for posteromedial corner reconstruction, with early results indicating that anatomic reconstruction can restore valgus stability and improve patient function. A thorough understanding of the anatomy, physical examination findings, and imaging characteristics will aid the physician in the management of these injuries.

Influences of Tumor Necrosis Factor-α on Lysyl Oxidases and Matrix Metalloproteinases of Injured Anterior Cruciate Ligament and Medial Collateral Ligament Fibroblasts.

The anterior cruciate ligament (ACL) fails to heal after injury, even after a primary surgical attempt. In contrast, the medial collateral ligament (MCL) can heal relatively well and restore the full joint function. The difference in intrinsic properties of these ligament cells can be due to their different responses to their local factors. TNF-α is considered to be an important chemical mediator in the wound healing of the ligaments. However, TNF-α-induced expression of lysyl oxidases (LOXs) and matrix metalloproteinases (MMPs) after injury is poorly understood. In this study, we use equi-biaxial stretch chamber to realize 12% stretch, which could mimic the injury to the ACL and MCL fibroblasts in vitro, and aim to determine the intrinsic differences between injured ACL and MCL by characterizing the differential expressions of LOXs and MMPs in response to TNF-α. The methods included Semiquantitative PCR, quantitative real-time PCR, Western blot, and zymography. We found that the mRNAs of LOXs had temporal increases in injured ACL and MCL. Moreover, the increases were higher in injured MCL than those in injured ACL (up to 1.77 ± 0.13-fold in LOX, 1.73 ± 0.21-fold in LOXL-1, 2.23 ± 0.27-fold in LOXL-2, 1.95 ± 0.11-fold in LOXL-3, 1.97 ± 0.28-fold in LOXL-4). On the other hand, the expressions of MMPs in injured ACL were much more prominent than those in injured MCL fibroblasts (up to 2.63 ± 0.20-fold in MMP-1, 3.73 ± 0.18-fold MMP-2, 1.58 ± 0.11-fold MMP-3, 4.23 ± 0.31-fold MMP-12). Similar results were observed at the protein level. The differential expression of LOXs and MMPs between the injured ACL and MCL fibroblasts in this study may help explain the healing abilities of the two different ligaments.

A novel rabbit model of early osteoarthritis exhibits gradual cartilage degeneration after medial collateral ligament transection outside the joint capsule.

Though many surgical animal models have been used to induce osteoarthritis (OA) of the knee joint, they always open the capsule of the joint. Any surgical procedures that incises the capsule may cause inflammation, pain, and possibly altered gait. One common disadvantage of these surgically induced animal models is that they may affect the initial structures and synovial fluid in joint. These animal models may not be suitable for research into synovial fluid changes during early OA. This study aimed to create an animal model of early OA by resecting the medial collateral ligament (MCL) outside of the capsule. At 1, 2, 3, 4, 5 and 6 weeks after surgery, eight knees from each group were harvested. The joint gap was measured on posteroanterior radiographs after MCL-transection (MCLT). Gross examination and histological analysis were performed to evaluate cartilage damage to the medial femoral condyles, and knee joints were scanned using a Micro-CT system. The MCLT group experienced early stage OA from 3 to 6 weeks according to the histological scores. IL-6, MMP-1 and MMP-13 content in the synovial fluid were higher after MCLT than anterior cruciate ligament transection (ACLT) at 1 and 2 weeks.

Intolerancia a tornillo interferencial tibial. Una rara complicación en la Cirugía de reconstrucción del ligamento cruzado anterior / Intolerance to tibial fixation devices for ACL repair. A rare complication

Introducción: Se presenta una serie de casos de pacientes que han desarrollado bultoma, secreción y dolor pretibial tras la reconstrucción del LCA fijado con tornillos reabsorbibles (HA-PLLA [Hidroxiapatita- ácido L-poliláctico]). Método: Se revisan de manera retrospectiva todas las reconstrucciones de LCA realizadas entre 2008 y 2014 para identificar las complicaciones relacionadas con el sistema de fijación bioabsorbible. Durante ese periodo de 6 años se realizaron 620 reconstrucciones de LCA usando el tornillo bioabsorbible (HA-PLLA) para la fijación tibial del injerto tetrafascicular de isquiotibiales. Resultados: Nueve pacientes (1,45%) con un rango de edad de 29,8 (19-44 años), presentaron el periodo postoperatorio dolor, tumoración y secreción pretibial en la zona de inserción del tornillo. Todos presentaron marcadores inflamatorios normales. Todos los pacientes requirieron desbridamiento quirúrgico, y retirada de los restos del tornillo y de los tejidos reactivos. Se evidenció infección en 4 cultivos intraoperatorios. La anatomía patológica reveló restos detríticos birrefringentes en el citoplasma de los macrófagos. La retirada de los restos del tornillo y el desbridamiento y curetaje del túnel, supuso la recuperación completa de todos los pacientes de nuestra serie. Conclusiones: La tumoración pre-tibial como respuesta biológica adversa, debe considerarse como una posible complicación en la reconstrucción del LCA. Se aprecia una incidencia de 1,45% de reacción pretibial tras el uso de tornillos reabsorbibles (HA-PLLA) en tibia proximal en la reconstrucción de LCA

Background: We report a series of cases that presented as pre-tibial cyst, swelling and pain following anterior cruciate ligament (ACL) reconstruction using bioabsorble fixation devices (HA-PLLA). Methods: All ACL reconstructions were done between 2008 and 2014 reviewed retrospectively to identify complications related to bioabsorbable fixation devices. During this period of 6 years, 620 ACL reconstructions were performed using the bioabsorbable screw (HA-PLLA) for tibial fixation of the quadrupled hamstring autograft. Results: Nine patients (1,45%) with mean age of 29,8 (19-44) years, presented in the post-operative period, pre-tibial pain, cyst and swelling in tibial screw site. All of them had normal inflammatory markers. All of these patients underwent surgical debridement, which revealed remnants of screw and reactive material. There was evidence of infection in 4 intra-operative specimen cultures. Histopathology revealed detritic birefringent remains in macrophages cytoplasm. Removal of screw debris and curettage of the tunnel resulted in complete recovery of all patients in our series. Conclusions: Pre-tibial cyst as an adverse biological response should be considered as a possible complication in ACL reconstruction. We report a 1,45% of pre-tibial reaction in patients undergoing ACL reconstruction with bio-absorbable (HAPLLA) interference screw fixation for the proximal tibia

Case report - calcification of the medial collateral ligament of the knee with simultaneous calcifying tendinitis of the rotator cuff.

BACKGROUND: Calcification of the medial collateral ligament (MCL) of the knee is a very rare disease. We report on a case of a patient with a calcifying lesion within the MCL and simultaneous calcifying tendinitis of the rotator cuff in both shoulders. CASE PRESENTATION: Calcification of the MCL was diagnosed both via x-ray and magnetic resonance imaging (MRI) and was successfully treated surgically. Calcifying tendinitis of the rotator cuff was successfully treated applying conservative methods. CONCLUSION: This is the first case report of a patient suffering from both a calcifying lesion within the medial collateral ligament and calcifying tendinitis of the rotator cuff in both shoulders. Clinical symptoms, radio-morphological characteristics and macroscopic features were very similar and therefore it can be postulated that the underlying pathophysiology is the same in both diseases. Our experience suggests that magnetic resonance imaging and x-ray are invaluable tools for the diagnosis of this inflammatory calcifying disease of the ligament, and that surgical repair provides a good outcome if conservative treatment fails. It seems that calcification of the MCL is more likely to require surgery than calcifying tendinitis of the rotator cuff. However, the exact reason for this remains unclear to date.

Combined effect of ligament stem cells and umbilical-cord-blood-derived CD34+ cells on ligament healing.

Transplantation of ligament-tissue-derived stem cells has become a promising approach in the repair of injured ligament. Neovascularization plays an important role in ligament healing and remodeling. Recently, human umbilical-cord-blood-derived CD34+ cells have been reported to contribute to neoangiogenesis. Therefore, we performed a series of experiments to test our hypothesis that the combination of medial collateral ligament stem cells (MCL-SCs) and umbilical-cord-blood-derived CD34+ cells has synergistic effects on tendon healing. MCL-SCs and umbilical-cord-blood-derived CD34+ cells were isolated and cultured. Rat MCL injury was treated by MCL-SCs and/or CD34+ cells. Response to the cell therapy was assessed by gross observation, histological evaluation and biomechanical testing at 2 and 4 weeks after each treatment. Although each cell therapy group induced macroscopic and morphological recovery in healing MCLs, the combined use of MCL-SCs/CD34+ cells led to further improvement in healing quality. Capillary density was significantly higher in the CD34+ cell transplantation groups than in the other groups at week 2. Biomechanical testing demonstrated that the failure load of the healing ligament was greatest in the combination therapy group. The combination of MCL-SCs and CD34+ cells as a cell therapeutic thus enhances healing and restores biomechanical function toward normal after MCL injury. The findings obtained in our study suggest that the combination of MCL-SCs and CD34+ cells transplantation represents a promising strategy for ligament injury.