The effect of different alignment strategies on trochlear orientation after total knee arthroplasty.

PURPOSE: When planning and delivering total knee arthroplasty (TKA), there are multiple coronal alignment strategies such as functional alignment (FA), kinematic alignment (KA), mechanical and adjusted mechanical alignment (MA, aMA). Recent three-dimensional and robotic-assisted surgery (RAS) studies have demonstrated that KA potentially better restores the trochlear anatomy than MA. The purpose of this study was to compare the restoration of the native trochlear orientation in patients undergoing RAS TKA using four different alignment strategies. It was hypothesised that FA would result in the lowest number of outliers. METHODS: This is a prospective study of 200 patients undergoing RAS-TKA with a single implant. All patients were analysed for MA and KA prebalancing, and 157 patients received aMA and 43 patients FA with intraoperative balancing. Preoperative transverse computed tomography scans were used to determine the posterior condylar axis (PCA), lateral trochlear inclination (LTI) angle, sulcus angle (SA) and anterior trochlear line (ATL) angle. Implant measurements were obtained using a photographic analysis. Intraoperative software data combined with implant data and preoperative measurements were used to calculate the differences. Outliers were defined as ≥3° of alteration. Trochlea dysplasia was defined as LTI < 12°. RESULTS: Native transepicondylar PCA had a median of 2°, LTI 18°, SA 137°, ATL 4°. LTI outliers were observed in 47%-60% of cases, with KA < FA < aMA < MA. For ATL, the range of outliers was 40.5%-85%, KA < FA < aMA < MA. SA produced 81% of outliers. Of all median angle values, only LTI when using KA was not significantly altered compared to the native knee. CONCLUSION: There is a significant alteration of trochlear orientation after TKA, regardless of the alignment strategy used. KA produced the lowest, but a substantial, number of outliers. The uniform design of implants causes the surgeon to compromise on balance in flexion versus trochlear position. The clinical relevance of this compromise requires further clinical investigations. LEVEL OF EVIDENCE: Level II, prospective cohort study.

Increased Femoral Component Flexion and No Difference in Slope in Robotic- versus Computer-Assisted Total Knee Arthroplasty When Targeting Mechanical Alignment.

Robotic-assisted surgery (RAS) in total knee arthroplasty (TKA) is becoming popular due to better precision, when compared with other instrumentation. Although RAS has been validated in comparison with computer-assisted surgery (CAS), data from clinical settings comparing these two techniques are lacking. This is especially the case for sagittal alignment. Whereas pure mechanical alignment (MA) aims for 0 to 3 degrees of flexion of the femoral component and 3° of posterior slope for the tibial component, adjusted MA (aMA) mostly used with RAS allows for flexing of the femoral component for downsizing and increase of slope for an increase of the flexion gap. In the present study, we compared sagittal alignment after TKA using RAS with aMA and CAS targeting MA, which has been the standard in the center for more than 10 years. We analyzed a prospectively collected database of patients undergoing TKA in a single center. Femoral component flexion and tibial slope were compared for both techniques. In 140 patients, 68 CAS and 72 RAS, we found no difference in tibial slope (p = 0.661), 1° median femoral component flexion (p = 0.023), and no difference in outliers (femur, p = 0.276, tibia, p = 0.289). RAS slightly increases femoral component flexion, but has no influence on tibial slope, when compared with CAS in TKA. If MA is the target, RAS provides no benefit over CAS for achieving the targeted sagittal alignment. LEVEL OF EVIDENCE: Level III retrospective study.

Severe obesity in total knee arthroplasty occurs in younger patients with a greater healthcare burden and complication rate.

BACKGROUND: Knee osteoarthritis in the presence of severe obesity (BMI ≥ 40) is becoming an increasing presentation to healthcare services. When progressing to arthroplasty, this group is known to have higher complication rates. METHOD: A retrospective cohort study at a tertiary referral centre (UK) with all sequential patients undergoing TKA between 2019 and 2020 included following identification from the UK National Joint Registry. Patients were divided by BMI < 40 and BMI ≥ 40 (86, 16.3%). Analysis of BMI with pre-operative parameters including age, ASA, and blood parameters was performed. Primary outcome was re-operation rate. Secondary outcomes included length of stay, complications, and re-admission. RESULTS: Five hundred and twenty-eight sequential TKA patients were included. The BMI < 40 group (442 patients, 83.7%) were mean 5.4 years younger (p < 0.001), had a higher ASA grade (p < 0.001) lower albumin (p < 0.001) and higher HbA1c (p < 0.001) than the BMI ≥ 40 group (86 patients, 16.3%). The BMI ≥ 40 group had a higher rate of re-operation (8% vs 2%, p = 0.012), and longer length of stay (mean 1.2 days longer p < 0.001), most commonly due to wound discharge, which alongside dehiscence was significantly higher (11.6% vs 4.3% p = 0.02). Overall, re-admission rates were also higher (18.6% vs 6.1% p = 0.06) with wound dehiscence, superficial infection, and deep infection the most common causes. CONCLUSIONS: Those patients undergoing TKA with a BMI ≥ 40 are younger and have higher reoperation rates, greater length of stay, higher re-admission rates and more postoperative complications, providing a target for the development of pre-operative optimisation programmes.

MRI Criteria for Healing at 1 Year After Repair of a Traumatic Meniscal Tear.

BACKGROUND: Meniscal repair for a traumatic meniscal tear is increasingly used to preserve the meniscus. Interpreting postoperative magnetic resonance imaging (MRI) scans remains challenging, especially in symptomatic patients. There is a lack of reliable MRI criteria to affirm the healed character of a traumatic meniscal injury repair. PURPOSE: To identify relevant MRI criteria for meniscal healing after meniscal repair. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: We prospectively included all patients with a traumatic meniscal injury who underwent either an isolated meniscal repair or a repair during a concomitant anterior cruciate ligament reconstruction. A standardized preoperative and postoperative clinical evaluation was performed, along with collection of functional scores-Knee injury and Osteoarthritis Outcome Score, International Knee Documentation Committee, Lysholm Score, and 36-Item Short Form Health Survey. An MRI scan was performed 1 year postoperatively and compared with the preoperative MRI scan. The following MRI aspects were analyzed: variation of morphology and fat-saturated (FS) T2 intensity signal and pre- and postoperative tear diastasis measurement. RESULTS: Fifty patients (age, mean ± SD, 28.7 ± 8.5 years [range, 16-45 years]) who were 1 year postoperative were included. All patients were considered clinically healed had the same MRI characteristics. A signal change (FS T2) was observed from a high signal intensity fluid to a nonfluid moderate signal intensity. The morphology of the lesion was more complex: from the initial lesion, line ramifications appeared, creating the appearance of tree branches. The tear diastasis decreased (from 2.3 ± 0.5 mm [range, 1.3-3.5] to 1.1 ± 0.28 mm [range, 0.5-1.5]). CONCLUSION: MRI criteria confirming meniscal healing after traumatic meniscal repair at 1 year were identified: a change in the intrameniscal signal becoming nonfluid and moderate in intensity; a reduction in tear diastasis to <1.5 mm; and a change in the signal morphology of the repaired meniscus.

Contribution of the Medial Hamstrings to Valgus Stability of the Knee.

Background: Multiligament knee injuries involving the medial side are common. When performing surgical reconstruction, use of the medial hamstrings (HS) as grafts remains controversial in this setting. Purpose: To determine the role of the medial HS in stabilizing the valgus knee for different types of medial-sided knee injury. Study Design: Controlled laboratory study. Methods: A biomechanical study on 10 cadaveric knees was performed. Valgus load (force moment of 10 N/m) was applied at 0°, 30°, and 60° of flexion, and the resultant rotation was recorded using an optoelectronic motion analysis system. Measurements were repeated for 4 different knee states: intact knee, superficial medial collateral ligament (sMCL) injury, deep medial collateral ligament (dMCL) injury, and posterior oblique ligament (POL) injury. For each state, 4 loading conditions (+ loaded; - unloaded) of the semitendinosus (ST) and gracilis (GRA) tendons were tested: ST+/GRA+, ST+/GRA-, ST-/GRA+, and ST-/GRA-. Results: At 0° of flexion, combined unloading of the ST and GRA (ST-/GRA-) increased valgus laxity on the intact knee compared with the ST+/GRA+ condition (P < .05). For all medial-sided injury states (isolated sMCL; combined sMCL and dMCL; and combined sMCL, dMCL, and POL damage), ST-/GRA- increased valgus laxity at 0° and 30° of flexion versus ST+/GRA+ (P < .05 for all). The absolute value of valgus laxity increased with the severity of medial-sided ligament injury. Isolated ST unloading increased valgus laxity for the intact knee and the MCL-injured knee (combined sMCL and dMCL) at 0° of flexion (P < .05 vs ST+/GRA+). Isolated unloading of the GRA had no effect on valgus knee stability. Conclusion: The medial HS tendons contributed to the stabilization of the knee in valgus, and this was even more important when the medial side was severely affected (POL damage). This stabilizing effect was greater between 0° and 30°, in which the POL is the main valgus stabilizer. Clinical Relevance: When deciding on graft selection for multiligament knee injury reconstruction, the surgeon should be aware of the effect of harvesting the medial HS tendon on valgus laxity.

Ligament Healing After Anterior Cruciate Ligament Rupture: An Important New Patient Pathway?

Recent studies have shown satisfactory functional results after spontaneous healing of a ruptured anterior cruciate ligament (ACL). However, current literature on this topic may exclude important parting selection, outcome measures, and long-term results. Rehabilitation protocols applied in those studies, as well as objective assessments appear far from the usual gold standard after ACL reconstruction. Ideally, outcomes measures should be based on the same testing procedures that are recommended to clear an athlete to return to sport following ACL reconstruction. There is still a lot to understand in how an injured ACL may heal, and therefore ACL injury management should be individualized to each patient and carefully discussed.

Return-to-sport criteria after isolated meniscus suture: Scoping review of the literature.

BACKGROUND: Follow-up care including rehabilitation therapy after isolated meniscal repair remains to be standardized. Thus, no standard criteria are available for the return-to-running (RTR) or return-to-sport (RTS). The objective of this study was to identify criteria for RTR and RTS after isolated meniscal repair, based on a review of the literature. HYPOTHESIS: Return-to-sport criteria after isolated meniscal repair have been published. METHODS: We performed a scoping review of the literature using the methodology developed by Arksey and O'Malley. The terms "menisc*" and "repair" and "return-to-sport" or "return to play" or "return to run" or "rehabilitation" were used to search the PubMed database on 1st March 2021. All relevant studies were included. All RTR and RTS criteria were identified, analyzed, and classified. RESULTS: We included 20 studies. Mean RTR and RTS times were 12.9 and 20 weeks, respectively. Clinical, strength, and performance criteria were identified. The clinical criteria included full range-of-motion recovery with no pain, quadriceps wasting, or joint effusion. Strength criteria were a quadriceps and hamstring deficit, no greater than 30% and 15% for RTR and RTS, respectively, compared to the normal side. Performance criteria were successful completion of proprioception, balance, and neuromuscular tests. RTS rates ranged from 80.4% to 100%. CONCLUSION: Patients must meet clinical, strength, and performance criteria before resuming running and sports. The level of evidence is low, due to the heterogeneity and generally arbitrary choice of criteria. Further large-scale studies are therefore needed to validate and standardize RTR and RTS criteria. LEVEL OF EVIDENCE: IV.

A balance between native footprint coverage and overlap of the anterolateral meniscal root in tibial tunnel positioning during anterior cruciate ligament reconstruction: A 3D MRI study.

BACKGROUND: Tibial footprint of anterior cruciate ligament (ACL) is situated close to the anterior lateral meniscal root (ALMR) attachment. PURPOSE: To investigate the impact of the size and location of the tibial tunnel for ACL reconstruction on the ACL footprint coverage and overlap to the ALMR. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty knee MRI scans from twenty healthy subjects were recruited, and three-dimensional (3D) tibia models were created to show the tibial attachment sites of ACL and ALMR. Surgical simulation of the tibial tunnel drilling was performed on each 3D model, entering the joint at an angle set at 60 degrees from the tibial plateau plane and 55 degrees from the posterior tibial condylar axis, with analysis for six different drill sizes; 7.5, 8, 8.5, 9, 9.5 and 10 mm; and nine locations; the center of the ACL attachment and eight locations 2% of the tibial width apart surrounding it. The width of the tibial plateau, the distance between ACL and ALMR attachment centers, and the size and location of the potential tibial tunnel were evaluated to determine association with the area of the ACL footprint coverage and ALMR overlap using a linear mixed effects model. RESULTS: A large tunnel (p <.001), a central and anterior location (p <.029), and small tibial width (p =.015) were all associated with larger coverage of the ACL footprint. A large tunnel (p <.001), posteriorly and laterally located (p ≤ 0.001), and a small distance between the ACL and ALMR centers (p =.001) were significantly associated with a larger ALMR overlap. The association of the tunnel size to ALMR overlap reduced with a medial tunnel location. CONCLUSIONS: The short distance between the centers of the ALMR attachment and native ACL footprint suggests that the ALMR will always be susceptible to overlap when the tibial tunnel is drilled in ACL reconstruction. Small alterations in tunnel location can lead to a statistically significant alteration with the amount of ALMR overlap. To minimize this overlap, whilst maintaining acceptable coverage of the ACL footprint, a tibial tunnel positioned in a medial or anteromedial location from the center of the ACL footprint is recommended.

After MPFL reconstruction, femoral tunnel widening and migration increase with poor tunnel positioning and are related to poor clinical outcomes.

PURPOSE: Isolated MPFL reconstruction (iMPFLR) is increasingly used for the surgical treatment of treatment for recurrent patella dislocation. The purpose of this study was to evaluate the influence of tunnel widening and migration on clinical outcomes after iMPFL using a CT-scannographic analysis at 6 months postoperatively. METHODS: One hundred and sixty patients (91 females for 69 males) with an average age of 23 years [14-54] who underwent iMPFLR and had an evaluation scan at 6 months postoperatively were evaluated with a mean follow-up of 97 ± 89 months [12 to 166]. Functional International Knee Documentation Committee (IKDC) Score, Kujala score, and joint mobility were assessed preoperatively, at 6 months and at the latest follow-up. The IKDC and Kujala scores were expressed as the difference between pre- and postoperative scores (dIKDC and dKujala). The position of the femoral tunnel was assessed according to the Schöttle criteria on post-operative radiographic profiles. Tunnel widening (at three levels of measurement) and the migration of the center of the tunnel were studied on a CT-scan analysis at 6 months. Any correlation and regression between the evolution of the clinical scores and the measured scannographic parameters were investigated. The relationships between tunnel position and tunnel changes were also studied. RESULTS: Between pre- and post-op, the IKDC (45 ± 13 to 80 ± 15, p < 0.001) and Kujala (55 ± 11 to 87 ± 12, p < 0.001) scores were significantly improved. Patients with tunnel changes had decreased clinical and functional results at 6 months post-op of an iMPFLR (p < 0.001). These changes in the femoral tunnel, evidenced by a tunnel entrance widening and migration of the tunnel center, were related to an initial malposition of the tunnel (p < 0.001). CONCLUSION: In iMPFLR, changes in the femoral tunnel, corresponding to dilatation and migration of the tunnel center, may occur. These changes are increased by the initial malpositioning of the femoral tunnel and are correlated with less good clinical and functional outcomes. LEVEL OF EVIDENCE: Level IV.

Navigation in anterior cruciate ligament reconstruction: State of the art.

Computer navigation (CN) for anterior cruciate ligament (ACL) surgery has been used mainly for two purposes: to enhance the accuracy of tunnel position and to evaluate the kinematics of the ACL reconstruction (ACLR) and the stability achieved by different surgical techniques. Many studies have shown that navigation may improve the accuracy of anatomical tunnel orientation and position during ACL reconstructive surgery compared with normal arthroscopic tunnel placement, especially regarding the femoral side. At the same time, it has become the gold-standard method for intraoperative knee kinematic assessment, as it permits a quantitative multidirectional knee joint laxity evaluation. CN in ACL surgery has been associated with diverse problems. First, in most optic systems additional skin incisions and drill holes in the femoral bone are required for fixation of a reference frame to the femur. Second, additional radiation exposure and extra medical cost to the patient for preoperative planning are usually needed. Third, CN, due to additional steps, has more opportunities for error during preoperative planning, intraoperative registration, and operation. Fourth, soft tissues, including the skin and subcutaneous tissues, are usually not considered during the preoperative planning, which can be a problem for kinematic and stability assessment. Many studies have concluded that ACLR using a CN system is more expensive than conventional surgery, it adds extra time to the surgery and it is not mitigated by better clinical outcomes. This, combined with costs and invasiveness, has limited the use of CN to research-related cases. Future technology should prioritize less invasive intra-operative surgical navigation.

International Survey of Practice for Prophylactic Systemic Antibiotic Therapy in Hip and Knee Arthroplasty.

(1) Background: Prophylactic systemic antibiotics are acknowledged to be an important part of mitigating prosthetic joint infections. Controversy persists regarding optimal antibiotic regimes. We sought to evaluate current international antibiotics guidelines for total joint arthroplasty (TJA) of the hip and knee. (2) Methods: 42 arthroplasty societies across 6 continents were contacted and their published literature reviewed. (3) Results: 17 societies had guidelines; of which 11 recommended an antibiotic agent or antibiotic class (10-cephalosporin; 1-cloxacillin); 15 recommended antibiotic infusion within an hour of incision and 10 advised for post-operative doses (8-up to 24 h; 1-up to 36 h; 1-up to 48 h). (4) Conclusions: Prophylactic antibiotic guidelines for TJA are often absent or heterogenous in their advice.

Magnetic Resonance Imaging Assessment of Hamstring Graft Healing and Integration 1 and Minimum 2 Years after ACL Reconstruction.

BACKGROUND: An increase has been seen in the number of studies of anterior cruciate ligament reconstruction (ACLR) that use magnetic resonance imaging (MRI) as an outcome measure and proxy for healing and integration of the reconstruction graft. Despite this, the MRI appearance of a steady-state graft and how long it takes to achieve such an appearance have not yet been established. PURPOSE: To establish whether a hamstring tendon autograft for ACLR changes in appearance on MRI scans between 1 and 2 years and whether this change affects a patient's ability to return to sports. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients with hamstring tendon autograft ACLR underwent MRI and clinical outcome measures at 1 year and at a final follow-up of at least 2 years. MRI graft signal was measured at multiple regions of interest using oblique reconstructions both parallel and perpendicular to the graft, with lower signal indicative of better healing and expressed as the signal intensity ratio (SIR). Changes in tunnel aperture areas were also measured. Clinical outcomes were side-to-side anterior laxity and patient-reported outcome measures (PROMs). RESULTS: A total of 42 patients were included. At 1 year, the mean SIR for the graft was 2.7 ± 1.2. Graft SIR of the femoral aperture was significantly higher than that of the tibial aperture (3.4 ± 1.3 vs 2.6 ± 1.8, respectively; P = .022). Overall, no significant change was seen on MRI scans after 2 years; a proximal graft SIR of 1.9 provided a sensitivity of 96% to remain unchanged. However, in the 6 patients with the highest proximal graft SIR (>4) at 1 year, a significant reduction in signal was seen at final follow-up (P = .026), alongside an improvement in sporting level. A significant reduction in aperture area was also seen between 1 and 2 years (tibial, -6.3 mm2, P < .001; femoral, -13.3 mm2, P < .001), which was more marked in the group with proximal graft SIR >4 at 1 year and correlated with a reduction in graft signal. The patients had a high sporting level; the median Tegner activity score was 6 (range, 5-10), and a third of patients scored either 9 or 10. Overall, PROMs and knee laxity were not associated with MRI appearance. CONCLUSION: In the majority of patients, graft SIR on MRI did not change significantly after 1 year, and a proximal graft SIR <2 was a sensitive indicator for a stable graft signal, implying healing. Monitoring is proposed for patients who have a high signal at 1 year (proximal graft SIR >4), because a significant reduction in signal was seen in the second year, indicative of ongoing healing, alongside an improvement in sporting level. A reduction in tunnel aperture area correlated with a reduction in graft SIR, suggesting this could also be a useful measure of graft integration.

Optimal Combination of Femoral Tunnel Orientation in Anterior Cruciate Ligament Reconstruction Using an Inside-out Femoral Technique Combined With an Anterolateral Extra-articular Reconstruction.

BACKGROUND: The optimal orientation of the anterolateral extra-articular reconstruction (ALLR) femoral tunnel to avoid collision with the anterior cruciate ligament reconstruction (ACLR) femoral tunnel is not clearly defined in the literature. PURPOSE: To define the optimal combination of orientations of the ALLR femoral tunnel and the ACLR femoral tunnel using an inside-out technique to minimize risk of collision between these tunnels. STUDY DESIGN: Descriptive laboratory study. METHODS: Three-dimensional reconstruction of magnetic resonance imaging scans of 40 knees after an isolated ACLR with an inside-out femoral technique was used to assess the collision risk between ACLR and virtual ALLR tunnels. The optimal ACLR tunnel orientation was defined as having the safest distance from the ALLR tunnel. A second collision analysis was performed on all patients presenting with an optimal orientation of the ACLR tunnel to then define the optimal ALLR tunnel orientation. The potential for trochlear damage was also studied. A collision risk of 0% to 5% was considered acceptable and referred to as "low risk." RESULTS: The only ALLR tunnel orientation presenting a low risk of collision with the ACLR tunnel was with an axial angle of 40° anteriorly and a coronal angle of 0°. This orientation presented a 48% risk of trochlear damage with the guide wire of the ALLR tunnel. The more posterior the orientation of the ACLR, the larger the distance from the ALLR tunnel. Among the 22 patients presenting with an optimal ACLR tunnel (alpha angle superior to 40°), the ALLR tunnels aimed with 1 of these 3 orientations presented a low risk of tunnel collision and trochlear damage: 40° axial and 10° coronal, 35° axial and 5° coronal, or 30° axial and 0° coronal. CONCLUSION/CLINICAL RELEVANCE: To minimize risk of tunnel collision or trochlear damage when combining an inside-out ACLR with an ALLR, the ACLR tunnel should be performed with a posterior orientation (alpha angle >40°), and the ALLR tunnel should be aimed with 1 of 3 orientations: 40° axial and 10° coronal, 35° axial and 5° coronal, or 30° axial and 0° coronal.

Vancomycin Presoaking of the Graft Appears to Prevent Infection After Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis.

Background: Vancomycin presoaking of the graft has been shown to decrease infection rates in some case series of anterior cruciate ligament (ACL) reconstruction. Purpose: We sought to substantiate the efficacy of vancomycin presoaked grafts for the prevention of infection after ACL reconstruction. Methods: We performed a systematic review of Medline and OVID to assess the incidence of postoperative infection in studies comparing patients undergoing ACL reconstruction with the use of vancomycin presoaked ACL grafts and a control group of patients undergoing ACL reconstruction without the use of presoaked grafts. The efficacy of vancomycin presoaking was calculated using the Agresti-Coull confidence interval. Relative risk (RR) was calculated for every study and the total sample. Results: The 11 studies that met inclusion criteria comprised 24,298 patients. In patients with vancomycin presoaking of the graft, 1 infection was reported in 8764 cases (0.01% rate). In the studies with control groups that did not have vancomycin presoaked grafts, there were 125 infections in 15,534 ACL reconstructions (0.8% rate). The efficacy of vancomycin presoaking in preventing infection after ACL reconstruction was 99.9% (0.999%-1.000% CI). The overall RR obtained was 0.07 (0.03-0.16 CI). All included studies were retrospective cohort studies (level III). Conclusions: Vancomycin presoaking of the graft has been shown to decrease infection rates after ACL reconstruction in studies of low evidence level. This suggests the need for prospective randomized controlled trials addressing this issue so that recommendations on the routine use of vancomycin presoaking of ACL grafts can be made with confidence.

Vancomycin Presoaking of Hamstring Autografts in Anterior Cruciate Ligament Reconstruction Is Associated With Higher Magnetic Resonance Imaging Graft Signal Without Influencing Clinical Outcome.

PURPOSE: To present the clinical and imaging results of a series of patients undergoing anterior cruciate ligament reconstruction with vancomycin presoaking of the hamstring autograft compared with patients in the immediate period prior, when no vancomycin was used. METHODS: This was a retrospective sequential series of patients with anterior cruciate ligament reconstruction using either a graft protocol with no vancomycin presoaking (group 1, January 2013 to October 2015) or a graft protocol with vancomycin presoaking (group 2, November 2015 to December 2018). Lysholm and International Knee Documentation Committee scores were obtained at a minimum 24-month follow-up. Graft ruptures were recorded. Between 6 and 12 months' follow-up, magnetic resonance imaging (MRI) was obtained to evaluate graft healing and integration. RESULTS: There were 102 patients (72% male patients), with 40 in group 1 (mean age, 32.2 years) and 62 in group 2 (mean age, 32.3 years). A graft rupture occurred in 5 patients (13%) in group 1 and 6 patients (10%) in group 2 (P = .65). The median Lysholm score was 95 points (interquartile range [IQR], 86-100 points) in group 1 and 95 points (IQR, 90-100 points) in group 2 (P = .37). The median International Knee Documentation Committee score was 93 points (IQR, 82-99 points) in group 1 and 94 points (IQR, 86-99 points) in group 2 (P = .22). MRI evaluation of integration showed that 87 patients (90%) had no synovial fluid at the tunnel-graft interface, without a difference between groups (P = .24). On the basis of graft signal appearance, hyperintense grafts were found in 45 patients (46%); isointense, 45 (46%); and hypointense, 7 (7%). Group 1 had a higher prevalence of hypointense grafts, whereas group 2 had a higher prevalence of hyperintense and isointense grafts (P = .003). CONCLUSIONS: Vancomycin presoaking of hamstring grafts increased the number of hyperintense and isointense grafts on MRI. Additionally, more hypointense grafts were noted when vancomycin was not used, suggesting the presence of more mature grafts in the non-vancomycin group. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Posterolateral corner knee injuries: a narrative review.

Limited knowledge of the anatomy and biomechanics of the posterolateral corner (PLC) of the knee, coupled with poor patient outcomes with non-operative management, resulted in the PLC often being labelled as the 'dark side' of the knee. In the last two decades, extensive research has resulted in a better understanding of the anatomy and function of the PLC, and has led to the development of anatomic reconstructions that have resulted in improved patient outcomes.Despite considerable attention in the clinical orthopaedic literature (nearly 400 articles published in the last decade), a standardized algorithm for the diagnosis and treatment of the PLC is still lacking, and much controversy remains.Considering the literature review, there is not a reconstruction technique that clearly prevails over the others. As anatomic, biomechanical, and clinical knowledge of PLC injuries continues to progress, finding the balance between re-creating native anatomy and safely performing PLC reconstruction provides a big challenge. Treatment decisions should be made on a case-by-case basis. Cite this article: EFORT Open Rev 2021;6:676-685. DOI: 10.1302/2058-5241.6.200096.

Salmonella infection after anterior cruciate ligament reconstruction: A case report.

BACKGROUND: Infections after anterior cruciate ligament reconstruction (ACLR) are rare. No cases of Salmonella infection have been described to our knowledge. CASE SUMMARY: We describe a rare case of Salmonella infection in a 23-year-old patient following an ACLR. The patient presented with subacute septic arthritis, 26 d after a hamstring autograft ACLR. The pathogen, Salmonella enterica typhimurium was isolated by bacteriological sampling of the first arthroscopic lavage. Two arthroscopic lavages were required, with intravenous antibiotic therapy for two weeks with cefotaxime and ciprofloxacin, followed by oral antibiotics with amoxicillin and ciprofloxacin for a total duration of three months. This approach treated the infection but two years after the septic arthritis, faced with ongoing knee instability due to graft damage, a revision ACLR with a bone-tendon-bone graft was performed. At the last follow-up, full range of knee motion had been achieved and sports activities resumed. CONCLUSION: Infection after ACLR is rare and requires an early diagnosis and management in order to treat the infection and prevent arthritis-related joint cartilage destruction and damage to the graft.

Lateral tenodesis procedures increase lateral compartment pressures more than anterolateral ligament reconstruction, when performed in combination with ACL reconstruction: a pilot biomechanical study.

OBJECTIVES: Given the common occurrence of residual laxity and re-injury post anterior cruciate ligament reconstruction (ACLR), additional anterolateral procedures are increasingly used in combination with an ACLR. Despite the perception that there is a risk of over-constraining the lateral tibiofemoral (LTF) compartment, potentially leading to osteoarthritis, assessment on their effect on intra-articular compartment pressures is still lacking. Our objective was therefore, through a pilot biomechanical study, to compare LTF contact pressures after the most commonly used anterolateral procedures. METHODS: A controlled laboratory pilot study was performed using 4 fresh-frozen cadaveric whole lower limbs. Through 0° to 90° of flexion, LTF contact pressures were measured with a Tekscan sensor, located under the lateral meniscus. Knee kinematics were obtained in 3 conditions of rotation (NR: neutral, ER: external and IR: internal rotation) to record the position of the knees for each loading condition. A Motion Analysis system with a coordinate system based on CT scans 3D bone modelling was used. After an ACLR, defined as the reference baseline, 5 anterolateral procedures were compared: anterolateral ligament reconstruction (ALLR), modified Ellison, deep Lemaire, superficial Lemaire and modified MacIntosh procedures. The last 3 procedures were randomised. For each procedure, the graft was fixed in NR at 30° of flexion and with a tension of 20 N. RESULTS: Compared with isolated ACLR, addition of either ALLR or modified Ellison procedure did not increased the overall LTF contact pressure (all p>0.05) through the full range of flexion for the IR condition. Conversely, deep Lemaire, superficial Lemaire and modified MacIntosh procedure (all p<0.05) did increase the overall LTF contact pressure compared with ACLR in IR. No significant difference was observed in ER and NR conditions. CONCLUSION: This pilot study, comparing the main anterolateral procedures, revealed that addition of either ALLR or modified Ellison procedure did not change the overall contact pressure in the LTF compartment through 0° to 90° of knee flexion. In contrast, the deep and superficial Lemaire, and modified MacIntosh procedures significantly increased overall LTF contact pressures when the knee was internally rotated.

Different anterolateral procedures have variable impact on knee kinematics and stability when performed in combination with anterior cruciate ligament reconstruction.

OBJECTIVE: The optimal anterolateral procedure to control anterolateral rotational laxity of the knee is still unknown. The objective was to compare the ability of five anterolateral procedures performed in combination with anterior cruciate ligament reconstruction (ACLR) to restore native knee kinematics in the setting of a deficient anterior cruciate ligament (ACL) and anterolateral structures. METHODS: A controlled laboratory study was performed using 10 fresh-frozen cadaveric whole lower limbs with intact iliotibial band. Kinematics from 0° to 90° of flexion were recorded using a motion analysis three-dimensional (3D) optoelectronic system, allowing assessment of internal rotation (IR) and anteroposterior (AP) tibial translation at 30° and 90° of flexion. Joint centres and bony landmarks were calculated from 3D bone models obtained from CT scans. Intact knee kinematics were assessed initially, followed by sequential section of the ACL and anterolateral structures (anterolateral ligament, anterolateral capsule and Kaplan fibres). After ACLR, five anterolateral procedures were performed consecutively on the same knee: ALLR, modified Ellison, deep Lemaire, superficial Lemaire and modified MacIntosh. The last three procedures were randomised. For each procedure, the graft was fixed in neutral rotation at 30° of flexion and with a tension of 20 N. RESULTS: Isolated ACLR did not restore normal overall knee kinematics in a combined ACL plus anterolateral-deficient knee, leaving a residual tibial rotational laxity (p=0.034). Only the ALLR (p=0.661) and modified Ellison procedure (p=0.641) restored overall IR kinematics to the normal intact state. Superficial and deep Lemaire and modified MacIntosh tenodeses overconstrained IR, leading to shifted and different kinematics compared with the intact condition (p=0.004, p=0.001 and p=0.045, respectively). Compared with ACLR state, addition of an anterolateral procedure did not induce any additional control on AP translation at 30° and 90° of flexion (all p>0.05), except for the superficial Lemaire procedure at 90° (p=0.032). CONCLUSION: In biomechanical in vitro setting, a comparison of five anterolateral procedures revealed that addition of either ALLR or modified Ellison procedure restored overall native knee kinematics in a combined ACL plus anterolateral-deficient knee. Superficial and deep Lemaire and modified MacIntosh tenodeses achieved excellent rotational control but overconstrained IR, leading to a change from intact knee kinematics. LEVEL OF EVIDENCE: The level-of-evidence statement does not apply for this laboratory experiments study.