The distal tibiofibular syndesmosis is a reliable landmark for 3° varus tibial resection in total knee arthroplasty: a radiological evaluation on 1296 cases.

PURPOSE: The purpose of this study was to evaluate the reproducibility and the accuracy of distal tibiofibular syndesmosis (DTFS) as landmark to perform controlled varus tibial resections during total knee arthroplasty (TKA). The hypothesis was that DTFS can be used to perform an accurate 3° varus tibial cut. METHODS: A retrospective analysis on a consecutive series of standard weightbearing full-length anteroposterior views of the lower limbs radiographic images was conducted. For each radiograph, the hip-knee-ankle (HKA) angle, the angle between the tibial mechanical axis and the line connecting the centre of the tibial spines and the DTFS (tibiofibular angle, TFA) and the medial proximal tibial angle (MPTA) were calculated. Each measurement was carried out twice by three independent observers, and intra- and inter-observer measurement reliability were assessed using the intraclass correlation coefficient (ICC) analysis. RESULTS: A total of 1296 lower limbs were analysed from a series of 648 weightbearing full-length anteroposterior radiographs. The ICC were > 90% for all measurements. The mean TFA value was 2.94 ± 0.68 (range 2.38-3.51). No differences were detected comparing the mean TFA value on the right and left limb (p = 0.795) as well as comparing the values in male and female patients (p = 0.691). Linear regression analysis did not find statistically significant correlation between TFA and MPTA, or TFA and HKA angles, respectively. CONCLUSION: The distal tibiofibular syndesmosis is a reliable and easy reproducible radiographic landmark that can be used when planning a 3° varus tibial cut. Future studies are needed to confirm the validity of this method also in clinical settings. LEVEL OF EVIDENCE: IV, retrospective case series.

Good long-term patients reported outcomes, return-to-work and return-to-sport rate and survivorship after posterior cruciate ligament (PCL)-based multiligament knee injuries (MLKI) with posteromedial corner tears as significant risk factor for failure.

PURPOSE: To assess the survival rate and associated risk factors of a wide cohort of patient's underwent surgical treatment for posterior cruciate ligament (PCL)-based multiligament knee injury (MLKI) at long-term follow-up and to investigate the long-term patient's reported outcomes (PROMS) and functional activity. METHODS: All cases of PCL-based MLKI performed at one single sport-medicine institution were extracted and patient's with a minimum 2 years of follow-up included. VAS, Lysholm, KOOS, Tegner Activity level scores, the incidence and time of return to sport (RTS) and return to work (RTW) were collected before, after surgery and at final follow-up. A multivariate logistic regression was performed to investigate the outcomes associated with the patient's acceptable symptoms state (PASS) for each sub-score of the KOOS. The Kaplan-Meier method with surgical failure (re-operation to one of the reconstructed ligaments) as endpoint was used to perform the survivorship analysis for the entire cohort. RESULTS: Forty-two patients were included and evaluated at an average of 10 years. All PROMS significantly improved from pre- to post-surgery (range ηp2 0.21-0.43, p < 0.05) except for the Tegner score which significantly improved from pre-surgery and to final follow-up (ηp2 = 0.67, p < 0.001). RTW was achieved in the 95.2% after 2.4 ± 1.9 months. RTS was achieved in 78.6% after 6.7 ± 5.0 months. The higher number of surgeries were the significant negative predictors of PASS for the KOOS sub-scales Sport (p = 0.040) and Quality of Life (p = 0.046), while the presence of meniscal lesions was a significant negative predictor of PASS only for the KOOS sub-scale of Sport (p = 0.003). Six patients (14.3%) underwent reoperation and were considered as surgical failures. The global survivorship was 95.2%, 92.6%, 87.1%, and 74.7% at 2, 5, 12, and 15 years, respectively. The survivorship in patient undergoing PMC reconstruction surgery was significantly lower (p = 0.004; HR 7.1) compared to patients without a PMC lesion. CONCLUSION: Good-to-excellent PROMS could be obtained and maintained at long-term follow-up after surgery, with the higher number of surgeries and meniscal lesions as significant negative predictors of the PASS. Moreover, the presence of a PMC lesion significantly increases the risk of the PCL reconstruction failure. LEVEL OF EVIDENCE: III.

Management of anterior cruciate ligament revision in adults: the 2022 ESSKA consensus part III-indications for different clinical scenarios using the RAND/UCLA appropriateness method.

PURPOSE: The aim of the ESSKA 2022 consensus Part III was to develop patient-focused, contemporary, evidence-based, guidelines on the indications for revision anterior cruciate ligament surgery (ACLRev). METHODS: The RAND/UCLA Appropriateness Method (RAM) was used to provide recommendations on the appropriateness of surgical treatment versus conservative treatment in different clinical scenarios based on current scientific evidence in conjunction with expert opinion. A core panel defined the clinical scenarios with a moderator and then guided a panel of 17 voting experts through the RAM tasks. Through a two-step voting process, the panel established a consensus as to the appropriateness of ACLRev for each scenario based on a nine-point Likert scale (in which a score in the range 1-3 was considered 'inappropriate', 4-6 'uncertain', and 7-9 'appropriate'). RESULTS: The criteria used to define the scenarios were: age (18-35 years vs 36-50 years vs 51-60 years), sports activity and expectation (Tegner 0-3 vs 4-6 vs 7-10), instability symptoms (yes vs no), meniscus status (functional vs repairable vs non-functional meniscus), and osteoarthritis (OA) (Kellgren-Lawrence [KL] grade 0-I-II vs grade III). Based on these variables, a set of 108 clinical scenarios was developed. ACLRev was considered appropriate in 58%, inappropriate in 12% (meaning conservative treatment is indicated), and uncertain in 30%. Experts considered ACLRev appropriate for patients with instability symptoms, aged ≤ 50 years, regardless of sports activity level, meniscus status, and OA grade. Results were much more controversial in patients without instability symptoms, while higher inappropriateness was related to scenarios with older age (51-60 years), low sporting expectation, non-functional meniscus, and knee OA (KL III). CONCLUSION: This expert consensus establishes guidelines as to the appropriateness of ACLRev based on defined criteria and provides a useful reference for clinical practice in determining treatment indications. LEVEL OF EVIDENCE: II.

The technique of cement application has no influence on cement intrusion in total knee arthroplasty: randomized study comparing three different techniques.

PURPOSE: The aim of the study was to compare the distance of intrusion of the cement into the bone in different areas both in the femur and the tibia in vivo, measured in the radiograph after implanting a total knee arthroplasty (TKA) with three different cement techniques. METHODS: A prospective randomized study of 90 consecutive patients operated on at our institution with a cemented U2 Knee System TKA and medium viscosity Simplex P® bone cement. After pulse lavage, the cement was applied on the bone surfaces (group 1), on the implant surfaces (group 2) or both on the bone and the implant surfaces (group 3). The cement intrusion was measured in the postoperative radiographs in eight different regions in the tibial component and in six regions in the femoral component. The cement employed was calculated by weighting the cement after mixing and weighting the discarded cement. RESULTS: The average intrusion of the cement was similar in all three groups of cementing techniques in the femoral components (1.6 mm; p = 0.386), and in the tibial components (2.6 mm; p = 0.144). The intrusion of the cement in the tibia was greater in women than in men (p = 0.04). We used 21.1 (SD 5.8) g of cement in average. The amount of cement employed was greater when the cement was applied on both (implant and bone) surfaces (group 3: 24.03 g in average) than when it was applied only on the bone (group 1: 20.13 g; p = 0.01) or only on the implants (group 2: 19.20 g; p = 0.001). The amount of cement employed was greater in men than in women (p = 0.002) and it was also greater when a PS femoral component was used (p = 0.03). The amount of cement employed was directly correlated with the height of the patients (p = 0.01) and with the bigger size of the components (p < 0.001). CONCLUSION: All three cement application techniques have similar intrusion distance of the cement into the bone, and the intrusion depth of the cement into the trabecular tibial bone is greater than the minimum suggested for fixation.

Increased posterior translation but similar clinical outcomes using ultracongruent instead of posterior stabilized total knee arthroplasties in a prospective randomized trial.

PURPOSE: The aim of this study was to compare the posterior tibial translation after ultracongruent (UC) and posterior-stabilized (PS) total knee arthroplasty (TKA) with two different UC with different heights in the anterior lip, and two different PS designs. This study also aimed to compare the range of motion (ROM) and outcomes scores after the use of these TKA models. It was hypothesised less posterior tibial translation after PS than after UC TKA, and less posterior tibial translation with a higher anterior lip in the UC insert than with a lower one. METHODS: It was designed as a prospective randomized study of a group of 120 patients operated with a cemented TKA. To clarify the main purpose of the study, four groups were analysed using different polyethylene designs: Triathlon PS insert in group one, Triathlon UC insert in group two, U2 PS insert in group three and U2 UC insert in group four. One year after surgery, a forced posterior drawer with a Telos Stress applying 15 kg of force posteriorly on the proximal tibia at 90° of knee flexion was analysed in the lateral radiograph. Limb alignment, tibial posterior slope and posterior condylar offset were also studied. RESULTS: 30 patients were included in each group. The average age was 73 years. There were 72.2% female and 27.8% male patients. There were no significant differences in any demographic or radiographic studied variables, preoperative range of motion (ROM) or preoperative Knee Society Scores (KSS) among the different groups. One year after surgery, the average postoperative ROM and the postoperative KSS Knee and KSS Function scores improved in respect of the preoperative values in all the groups. There were no significant differences in the postoperative outcome scores among the different groups (p = n.s.). Postoperative alignment of the limb, tibial posterior slope and posterior condylar offset were similar in the 4 study groups (p = n.s.). The postoperative posterior tibial translation was different between groups: the PS groups (groups 1 and 3) showed significant inferior values (p < 0.001) in respect of the UC groups (groups 2 and 4). There were no differences between both groups of PS models, but there was a significant increase in the posterior tibial translation of the Triathlon UC insert (11.2 mm SD 3.2) in respect of the U2 UC insert (6.1 mm SD 4.5) (p = 0.004). CONCLUSIONS: UC inserts restrict the posterior tibial translation after TKA less than PS inserts, but a design with a high anterior lip in the polyethylene UC insert can better control the posterior tibial translation than an insert with a small anterior lip. LEVEL OF EVIDENCE: Level I. Randomised controlled trial.

Lateral extraarticular tenodesis improves stability in non-anatomic ACL reconstructed knees: in vivo kinematic analysis.

PURPOSE: To carry out an in vivo kinematic analysis to determine whether adding a lateral extraarticular tenodesis (LET) for those patients with subjective instability and objective residual laxity after a transtibial (TT) anterior cruciate ligament reconstruction (ACLR) reduces anteroposterior and rotational laxity and to evaluate the 2-year follow-up clinical outcomes to analyze whether biomechanical changes determine clinical improvement or not. METHODS: A total of 19 patients with residual knee instability after TT ACLR who underwent a modified Lemaire LET were prospectively evaluated for at least 2-year follow-up. Preoperative, intraoperative, and 6 and 24-month postoperative kinematic analyses were carried out using the KiRA accelerometer and KT1000 arthrometer to look for residual anterolateral rotational instability and residual anteroposterior instability. Functional outcomes were measured with the single-leg vertical jump test and the single-leg hop test. Clinical outcomes were evaluated using the IKDC 2000, Lysholm, and Tegner scores. RESULTS: A significant reduction in anterolateral rotational instability was detected with the patient under anesthesia (from 3 ± 1.2 to 1.1 ± 1.1 m/s2; p < 0.05) as well as with the patient awake (from 2.1 ± 0.8 to 0.7 ± 1.4 m/s2; p < 0.05). A significant reduction in anteroposterior instability was only present under anesthesia (from 3.4 ± 1.9 to 2.1 ± 1.1 mm; p < 0.05), while no difference was present without anesthesia (from 2.3 ± 1.1 to 1.6 ± 1 mm; n.s.). Postoperative analysis of knee laxity did not show any significant variation from the first to the last follow-up. Both the single-leg vertical jump test and single-leg hop test improved significantly at the last follow-up (both p < 0.05). The mean values of both the IKDC and Tegner scores showed an improvement (p < 0.05 and p < 0.05, respectively), whereas that was not the case with the Lysholm score (n.s.). CONCLUSIONS: The modified Lemaire LET can improve the kinematics of a non-anatomic ACL reconstructed knee with residual subjective and objective instability. These kinematic changes were able to lead to an improvement in subjective stability as well as the function of the knee in a small cohort of recreationally active patients. At 2-year follow-up, the kinematic changes as well as the level of activity of the patients and the IKDC score show their improvement sustained. LEVEL OF EVIDENCE: Level IV.

The morphology of the femoral footprint of the anterior cruciate ligament changes with aging from a large semicircular shape to a small flat ribbon-like shape.

PURPOSE: Compare the differences in the morphology of the ACL femoral footprint between the cadavers of the young and elderly in consideration of the degenerative physiological process that occurs with aging. METHODS: The femoral footprint of the ACL was dissected in 81 knees of known gender and age (45 male/36 female). They were divided into four groups by age and gender, establishing 50 years as the cut-off point to divide patients by age. Three observers analyzed the femoral footprint dissections, and the shapes were described and classified. The area and morphometric characteristics of the femoral insertion of the ACL were determined and these were compared between genders and age groups. RESULTS: The femoral footprint of the ACL from the cadavers of males younger than 50 years of age presented a semicircular morphology in 90% of the cases. In males aged more than 50 years, a ribbon-like morphology was found in 96% of the cases. In women less than 50 years old, the semicircular morphology was observed in 93.7% of the cases. In women aged over 50 years old, the ribbon-like morphology was found in 95% of the cases. A significant difference was observed between the prevalence rates of the morphologies, area size and measurements of the younger and older groups (p < 0.001 for both genders). CONCLUSIONS: The femoral insertion of the ACL presents variations in its morphology, area and morphometric characteristics over time. It goes from a large semicircular shape that almost contacts the posterior articular cartilage to a smaller, flattened ribbon-like shape that moves away from the edge of the articular cartilage. It is bounded anteriorly by the lateral intercondylar ridge. These findings should be considered to avoid employing reconstruction techniques in which femoral tunnels with oval or rectangular shapes are used in patients under 50 years of age because they do not correspond to the morphology of the femoral insertion of the ACL in this age group.

Fixed-bearing unicompartmental knee arthroplasty provides a lower failure rate than mobile-bearing unicompartimental knee arthroplasty when used after a failed high tibial osteotomy: a systematic review and meta-analysis.

Despite the fact that the choice of bearing design has been thought to influence the functional outcomes and longevity of unicompartimental knee arthroplasty (UKA), there is a lack of clinical evidence supporting the decision-making process in patients who have undergone high tibial osteotomy (HTO). A systematic review of studies was carried out that reported the outcomes of fixed-bearing (FB) or mobile-bearing (MB) medial UKA in patients with a previous HTO. A random effect meta-analysis using a generalized linear mixed-effects model to calculate revision rates was done. Seven retrospective cohort studies were included for this study. Regarding the fixation method, 40 were the FB-UKA and 47 were MB-UKA. For both groups, the mean post-operative follow-up was 5.8 years. The survival rates were 92% for the FB-UKA with a mean follow-up of 10 years. For the MB-UKA, it ranged from 35.7 to 93%, with a mean follow-up of 4.2 years. For the FB, the time to revision was reported as 9.3 years, while 1.2, 2.5 and 2.91 years was reported for the MB. The results of the meta-analysis showed that the revision rate for the patients receiving a FB-UKA after failed HTO was 8%, compared to 17% in those who received an MB-UKA. The results of the review suggest that the use of the FB-UKA is associated with lower revision rates and a longer survival time than the MB-UKA and have similar functional ability scores.Level of evidence: III (systematic review of level-III studies).

The morphology of the tibial footprint of the anterior cruciate ligament changes with ageing from oval/elliptical to C-shaped.

PURPOSE: To further the current understanding of the modifications of the morphology of the ACL tibial footprint in healthy knees during the ageing process. The hypothesis is that there are differences in the morphology of the ACL tibial footprint between the cadavers of the young and elderly due to a degenerative physiological process that occurs over time. METHODS: The tibial footprint of the ACL was dissected in 64 knee specimens of known gender and age. They were divided into four groups by age and gender, setting 50 years of age as the cut-off point. Three observers analyzed the tibial footprint dissections and the shape was described and classified. RESULTS: The knees from the cadavers of males older than 50 years of age presented a "C" morphology in 85% of the cases. In the group of males aged less than 50 years, an oval/elliptical morphology was found in 85.7% of the cases. In the group of women over 50 years-old, the "C" morphology was observed in 82.3% of the cases. In women under the age of 50, the oval/elliptical morphology was found in 84.6% of the cases. A significant difference was observed between the prevalence rates of the morphologies of the younger and older groups (p < 0.001 for both genders). However, no differences were observed between males and females of the same age group (n.s.). CONCLUSIONS: The morphology of the tibial footprint of the ACL presents significant variations with ageing. It can go from an oval/elliptical shape to a "C" shaped morphology. The results of this work make for an advance in the individualization of ACL reconstruction based on the age and the specific morphology of the tibial footprint.

The posteromedial corner of the knee: an international expert consensus statement on diagnosis, classification, treatment, and rehabilitation.

PURPOSE: To establish recommendations for diagnosis, classification, treatment, and rehabilitation of posteromedial corner (PMC) knee injuries using a modified Delphi technique. METHODS: A list of statements concerning the diagnosis, classification, treatment and rehabilitation of PMC injuries was created by a working group of four individuals. Using a modified Delphi technique, a group of 35 surgeons with expertise in PMC injuries was surveyed, on three occasions, to establish consensus on the inclusion or exclusion of each statement. Experts were encouraged to propose further suggestions or modifications following each round. Pre-defined criteria were used to refine item lists after each survey. The final document included statements reaching consensus in round three. RESULTS: Thirty-five experts had a 100% response rate for all three rounds. A total of 53 items achieved over 75% consensus. The overall rate of consensus was 82.8%. Statements pertaining to PMC reconstruction and those regarding the treatment of combined cruciate and PMC injuries reached 100% consensus. Consensus was reached for 85.7% of the statements on anatomy of the PMC, 90% for those relating to diagnosis, 70% relating to classification, 64.3% relating to the treatment of isolated PMC injuries, and 83.3% relating to rehabilitation after PMC reconstruction. CONCLUSION: A modified Delphi technique was applied to generate an expert consensus statement concerning the diagnosis, classification, treatment, and rehabilitation practices for PMC injuries of the knee with high levels of expert agreement. Though the majority of statements pertaining to anatomy, diagnosis, and rehabilitation reached consensus, there remains inconsistency as to the optimal approach to treating isolated PMC injuries. Additionally, there is a need for improved PMC injury classification. LEVEL OF EVIDENCE: Level V.

The vancomycin soaking technique: no differences in autograft re-rupture rate. A comparative study.

PURPOSE: The main aim of this study was to evaluate the re-rupture risk after an anterior cruciate ligament reconstruction (ACL-R) using the vancomycin soaking technique and to compare it with the re-rupture risk in patients on whom this technique was not utilized. The secondary purpose was to compare the functional outcomes of those two subsets of patients operated on for ACL-R. The hypotheses are that the vancomycin soaking technique does not affect the re-rupture risk or the functional outcomes. MATERIAL AND METHODS: A retrospective historical cohort study was conducted. Two groups were compared in terms of the re-rupture rate (traumatic or atraumatic) and functional outcomes (International Knee Documentation Committee (IKDC), Tegner, and Lysholm). Group 1 consisted of patients that received pre-operative IV antibiotics. In group 2, the patients received pre-operative IV antibiotics along with a graft that had been presoaked in a vancomycin solution. A minimum follow-up of five years was required. RESULTS: There were 17 patients that suffered a re-rupture in group 1 (4.7%) and 15 in group 2 (3.9%) (n.s.). IKDC was 82.0 in group 1 and 83.9 in group 2 (p = 0.049); Tegner scored 4 in both groups (n.s.) and Lysholm was 90.3 in group 1 and 92.0 in group 2 (p = 0.015). CONCLUSION: The vancomycin soaking technique for ACL autografts is a safe procedure for the daily clinical practice, in terms of re-ruptures. Moreover, it does not impair functional outcomes after an ACL-R.

Evaluating for Tunnel Convergence in Anterior Cruciate Ligament Reconstruction With Modified Lemaire Tenodesis: What Is the Best Tunnel Angle to Decrease Risk?

PURPOSE: The purpose of this study was to analyze postoperative computed tomography (CT) scan evaluations of patients who had undergone a combined anterior cruciate ligament (ACL) reconstruction and modified Lemaire anterolateral tenodesis (ALT) with femoral fixation through a bony tunnel. METHODS: Postoperative CT scans of 52 patients who had undergone combined ACL and ALT were prospectively evaluated. ACL femoral tunnels were drilled through an anteromedial portal in the center of the native footprint. An ALT fixation tunnel was drilled 5 mm proximal to the lateral epicondyle, aiming at an inclination of 30° proximally and 30° anteriorly. Two independent observers evaluated the CT scans measuring any degree of collision, the shortest distance between the tunnels, and the inclination of the ALT tunnels. Measurements were carried out at both the cortical level and on a plane passing 1 cm deeper in the lateral condyle. RESULTS: At the level of the cortex, no convergence of the tunnels was identified. In 14 of 52 cases (26.9%), the shortest distance between the tunnels was less than 5 mm. Tunnel collision occurred in 8 of 52 cases (15.4%), and the bone bridge between the tunnels was less than 5 mm in 11 cases (21.1%) when the measurements were made on the deeper plane. When the inclination on the axial plane was less than 15°, a collision always (P < .001) occurs. When it was more than 20°, no collision occurred (P < .001). No correlation between convergence and the inclination of the ALT tunnel on the coronal plane was detected. CONCLUSIONS: To fix a modified Lemaire ALT through a femoral tunnel avoiding any interference with an anatomic femoral ACL tunnel, we recommend that the femoral tunnel be drilled with an inclination of at least 20° anteriorly. LEVEL OF EVIDENCE: IV, therapeutic case series.

Limb length discrepancy after total knee arthroplasty may contribute to suboptimal functional results.

PURPOSE: Limb length discrepancy (LLD) has been related to inferior outcomes after total hip arthroplasty (THA), but few studies have dealt with the LLD in primary total knee arthroplasty (TKA). The aims of the study were to examine the incidence of LLD after TKA and how it can influence in the outcomes scores. METHODS: We analysed preoperative, postoperative and changes in LLD in 460 patients who underwent a unilateral primary TKA. The measurements were done on digital full leg radiographs preoperatively and 6 months after surgery. The hip-knee-ankle (HKA) angle was also measured on these radiographs. Patients were evaluated with the Knee Society Score (KSS) preoperatively and 12 months after surgery. RESULTS: The average LLD was 1.1 mm in the preoperative period and changed to -0.8 mm in the postoperative (the 1.9 mm lengthening of the operated limb was statistically significant (p < 0.001)). LLD increase was correlated with preoperative HKA angle and with HKA angle changes. Only 8.3% of the patients had significant postoperative LLD (≥ 10 mm), but they had a significant worse function outcome in the KSS one year after surgery than patients with negligible postoperative LLD (< 10 mm) (76.7 vs 82.3; p = 0.02). CONCLUSIONS: Unlike THA surgery, significant LLD is not frequent after TKA surgery, but the functional results of the surgery can be suboptimal when it is present.

Posterolateral corner of the knee: an expert consensus statement on diagnosis, classification, treatment, and rehabilitation.

PURPOSE: To develop a statement on the diagnosis, classification, treatment, and rehabilitation concepts of posterolateral corner (PLC) injuries of the knee using a modified Delphi technique. METHODS: A working group of three individuals generated a list of statements relating to the diagnosis, classification, treatment, and rehabilitation of PLC injuries to form the basis of an initial survey for rating by an international group of experts. The PLC expert group (composed of 27 experts throughout the world) was surveyed on three occasions to establish consensus on the inclusion/exclusion of each item. In addition to rating agreement, experts were invited to propose further items for inclusion or to suggest modifications of existing items at each round. Pre-defined criteria were used to refine item lists after each survey. Statements reaching consensus in round three were included within the final consensus document. RESULTS: Twenty-seven experts (100% response rate) completed three rounds of surveys. After three rounds, 29 items achieved consensus with over 75% agreement and less than 5% disagreement. Consensus was reached in 92% of the statements relating to diagnosis of PLC injuries, 100% relating to classification, 70% relating to treatment and in 88% of items relating to rehabilitation statements, with an overall consensus of 81%. CONCLUSIONS: This study has established a consensus statement relating to the diagnosis, classification, treatment, and rehabilitation of PLC injuries. Further research is needed to develop updated classification systems, and better understand the role of non-invasive and minimally invasive approaches along with standardized rehabilitation protocols. LEVEL OF EVIDENCE: Consensus of expert opinion, Level V.

An intact fibula may contribute to allow early weight bearing in surgically treated tibial plateau fractures.

PURPOSE: The role of the proximal tibiofibular joint (PTFJ) in tibial plateau fractures is unknown. The purpose of this study was to assess, with finite-element (FE) calculations, differences in interfragmentary movement (IFM) in a split fracture of lateral tibial plateau, with and without intact fibula. It was hypothesized that an intact fibula could positively contribute to the mechanical stabilization of surgically reduced lateral tibial plateau fractures. METHODS: A split fracture of the lateral tibial plateau was recreated in an FE model of a human tibia. A three-dimensional FE model geometry of a human femur-tibia system was obtained from the VAKHUM project database, and was built from CT images from a subject with normal bone morphologies and normal alignment. The mesh of the tibia was reconverted into a geometry of NURBS surfaces. The fracture was reproduced using geometrical data from patient radiographs, and two models were created: one with intact fibula and other without fibula. A locking screw plate and cannulated screw systems were modelled to virtually reduce the fracture, and 80 kg static body weight was simulated. RESULTS: Under mechanical loads, the maximum interfragmentary movement achieved with the fibula was about 30% lower than without fibula, with both the cannulated screws and the locking plate. When the locking plate model was loaded, intact fibula contributed to lateromedial forces on the fractured fragments, which would be clinically translated into increased normal compression forces in the fractured plane. The intact fibula also reduced the mediolateral forces with the cannulated screws, contributing to stability of the construct. CONCLUSION: This FE model showed that an intact fibula contributes to the mechanical stability of the lateral tibial plateau. In combination with a locking plate fixation, early weight bearing may be allowed without significant IFM, contributing to an early clinical and functional recovery of the patient.

Fixation of a split fracture of the lateral tibial plateau with a locking screw plate instead of cannulated screws would allow early weight bearing: a computational exploration.

PURPOSE: To assess, with finite element (FE) calculations, whether immediate weight bearing would be possible after surgical stabilization either with cannulated screws or with a locking plate in a split fracture of the lateral tibial plateau (LTP). METHODS: A split fracture of the LTP was recreated in a FE model of a human tibia. A three-dimensional FE model geometry of a human femur-tibia system was obtained from the VAKHUM project database, and was built from CT images from a subject with normal bone morphologies and normal alignment. The mesh of the tibia was reconverted into a geometry of NURBS surfaces. A split fracture of the lateral tibial plateau was reproduced by using geometrical data from patient radiographs. A locking screw plate (LP) and a cannulated screw (CS) systems were modelled to virtually reduce the fracture and 80 kg static body-weight was simulated. RESULTS: While the simulated body-weight led to clinically acceptable interfragmentary motion, possible traumatic bone shear stresses were predicted nearby the cannulated screws. With a maximum estimation of about 1.7 MPa maximum bone shear stresses, the Polyax system might ensure more reasonable safety margins. CONCLUSIONS: Split fractures of the LTP fixed either with locking screw plate or cannulated screws showed no clinically relevant IFM in a FE model. The locking screw plate showed higher mechanical stability than cannulated screw fixation. The locking screw plate might also allow full or at least partial weight bearing under static posture at time zero.

Two-Year Clinical Results of Lateral Collagen Meniscus Implant: A Multicenter Study.

PURPOSE: To present the 2-year results of the use of the lateral Collagen Meniscus Implant (CMI) for the treatment of irreparable lateral meniscal lesions or partial lateral meniscal defects, to investigate the potential predictors of clinical results, and to monitor device safety. METHODS: Forty-three patients with a mean age of 30.1 ± 12.0 years were clinically evaluated 24 months after treatment of partial lateral meniscal defects with the CMI (Ivy Sports Medicine, Gräfelfing, Germany). We used the Lysholm score, the Tegner Activity Scale, a visual analog scale for pain (during strenuous activity, during routine activity, and at rest), a functional questionnaire, and a satisfaction questionnaire for the evaluation. All demographic and surgical parameters were used for multiple regression analysis to find outcome predictors. Serious adverse events and reoperations were monitored. RESULTS: All clinical scores significantly improved from preoperatively to final evaluation at 24.2 ± 1.9 months' follow-up. The Lysholm score improved significantly from 64.3 ± 18.4 preoperatively to 93.2 ± 7.2 at final follow-up (P = .0001). Functional improvement was detected from 6 months after surgery, whereas strenuous activities and knee swelling reached optimal results after 12 months. The highest pain ratings experienced during strenuous activity, during routine activity, and at rest significantly improved from 59 ± 29, 29 ± 25, and 20 ± 25, respectively, preoperatively to 14 ± 18, 3 ± 5, and 2 ± 6, respectively, at 2 years' follow-up (P = .0001). At final follow-up, 58% of patients reported activity levels similar to their preinjury values whereas 95% of patients reported that they were satisfied with the procedure. A higher body mass index, the presence of concomitant procedures, and a chronic injury pattern seemed to negatively affect the final outcomes. Serious adverse events with a known or unknown relation to the scaffold, such as pain, swelling, and scaffold resorption, were reported in 6% of patients, leading to CMI explantation, debridement, or synovectomy. CONCLUSIONS: The lateral CMI scaffold could be considered a potentially effective and safe procedure to treat both irreparable lateral meniscal tears and post-meniscectomy syndrome in appropriately selected patients. Chronic injury, high body mass index, and concomitant procedures have been shown to negatively affect the short-term results; however, the results appeared to slowly improve through the 24-month follow-up period. Thus patience is needed when evaluating the expectations for and results of the described procedure. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Femoral Tunnel Drilling Angles for Posteromedial Corner Reconstructions of the Knee.

PURPOSE: To determine the best angle to drill the femoral tunnels of the superficial medial collateral ligament (sMCL) and posterior oblique ligament (POL) with concomitant posterior cruciate ligament (PCL) reconstruction to avoid either short tunnels or tunnel collisions. METHODS: Eight cadaveric knees were studied. Double-bundle PCL femoral tunnels were arthroscopically drilled. Drilling of the sMCL and POL tunnels was performed in 4 different combinations of 0° and 30° axial (anteriorly directed) and coronal (proximally directed) angulations. Specimens were scanned with computed tomography to document the relations of the sMCL and POL tunnels to the intercondylar notch and PCL tunnels. A minimum tunnel length of 25 mm was required. RESULTS: When the sMCL femoral tunnel was drilled at 0° axial and 30° coronal (proximally directed) angulations or 30° axial (anteriorly directed) and 0° coronal angulations, the risk of tunnel collision with the PCL tunnels increased in comparison with the remaining evaluated angulations (P < .001). No POL tunnels collided with either PCL tunnel bundle with the exception of tunnels drilled at 0° axial and 30° coronal (proximally directed) angulations, which did so in 3 of 8 cases (P < .001). The minimum required tunnel length was obtained in all the sMCL and POL tunnels (P < .001 and P = .02, respectively). However, some of those angled at 0° on the axial plane violated the intercondylar notch. CONCLUSIONS: When one is performing posteromedial reconstructions with concomitant PCL procedures, the sMCL and POL femoral tunnels should be drilled anteriorly and proximally at both 30° axial and 30° coronal angulations. The POL femoral tunnel may also be angled 0° in the coronal plane. Tunnels at 0° axial angulations showed a shorter distance to the intercondylar notch and a higher risk of collision with the PCL tunnels. CLINICAL RELEVANCE: Specific drilling angles are necessary to avoid short tunnels or collisions between the drilled tunnels when sMCL and POL femoral tunnels are placed with concomitant PCL reconstruction.

Partial meniscus substitution with a polyurethane scaffold does not improve outcome after an open-wedge high tibial osteotomy.

PURPOSE: The aim of the study was to determine whether medial meniscal substitution with a polyurethane scaffold (Actifit(®)) improves the outcome of medial meniscal-deficient varus knees undergoing open-wedge high tibial osteotomy. METHODS: Sixty patients with symptomatic varus knees those who underwent open-wedge high tibial osteotomies were prospectively studied. In 30 patients, the medial meniscus was left with a defect larger than 25 mm (Group M). An Actifit(®) device was implanted (Group A) in the remaining 30 patients. Patients were functionally evaluated with WOMET, IKDC and VAS. Patient satisfaction was graded from 0 (not satisfied) to 4 (very satisfied). RESULTS: Both groups were comparable preoperatively. They had similar follow-up periods (31.2 months; range 24-47.5; n.s.). WOMET improved a mean of 53.4 ± 8.4 and 42.4 ± 17.2 points in Groups M and A, respectively (p = 0.002). IKDC improved a mean of 56.7 ± 12 and 50.3 ± 15.6 points in Groups M and A, respectively (n.s.). VAS dropped 5.9 ± 2.1 and 4.7 ± 2.8 points in Groups M and A, respectively (p = 0.006). Patient satisfaction averaged 3.3 ± 0.8 and 3.3 ± 1 in Groups M and A, respectively (n.s.). CONCLUSIONS: Patients with symptomatic varus knees were treated with open-wedge high tibial osteotomies, and a meniscectomy was improved more at short-term follow-up in most of the evaluated functional scores than those patients with concomitant implantation of a medial Actifit(®) implant. However, there was no difference in terms of patient satisfaction with the procedure. Based on the short-term functional results of this study, no data were provided to support medial meniscal substitution with a polyurethane scaffold when an open-wedge high tibial osteotomy is being performed. LEVEL OF EVIDENCE: Prospective comparative study, Level II.

Primary lipoma arborescens of the knee may involve the development of early osteoarthritis if prompt synovectomy is not performed.

BACKGROUND: Primary lipoma arborescens (LA) is a rare, benign intra-articular hyperplastic tumor that has been associated with osteoarthritis (OA). The aim of this study was to determine whether prompt synovectomy could avoid progressive joint degeneration in cases of primary LA of the knee. MATERIALS AND METHODS: A review of currently available literature about the disease was carried out. The clinical, histological and radiological records of a series of nine knees with primary LA diagnosed and treated between 2002 and 2012 were retrospectively reviewed. Eight of the knees had histological confirmation of LA and none had evidence of condropathy on the initial magnetic resonance image or degenerative changes at the initial radiographic examination. RESULTS: At the final follow-up no evidence of OA was found in the three knees that underwent synovectomy when symptoms did not last more than 1 year. The five knees in which synovectomy was delayed developed progressive joint degeneration. CONCLUSION: In this series, primary LA of the knee involved the development of early osteoarthritis when prompt synovectomy was not performed. Timely synovectomy is strongly recommended, if not mandatory. LEVEL OF EVIDENCE: IV.