High failure rate but promising clinical performance after implantation of a flexible medial meniscus prosthesis at 1-year follow-up.

PURPOSE: After unsatisfactory results in a first-in-human clinical investigation with an anatomically shaped medial meniscus prosthesis, the prosthesis and its fixation technique were altered. This interim analysis of a prospective single-arm clinical investigation aims to evaluate safety and clinical performance in a first-in-human study with the redesigned meniscus prosthesis system. METHODS: Ten patients suffering from medial postmeniscectomy pain syndrome were treated with the meniscus prosthesis. Patient-reported outcome measures were obtained at baseline and at 6-week, 3-, 6-, and 12-month follow-up. Radiographs and magnetic resonance imaging scans were obtained to evaluate joint degeneration and prosthesis location. RESULTS: The device alterations resolved the issues occurring with the previous design, but four prostheses were explanted after fixation failure or subluxation of the prosthesis. Five out of six patients who reached 1-year follow-up reported a clinically significant improvement of the knee injury and osteoarthritis outcome score pain subscale. Imaging revealed no adverse effects on joint degeneration. CONCLUSION: The failure mechanisms that occurred with the previous design have been resolved, but the new fixation technique introduced new safety issues. Improvement of positioning and fixation techniques are considered essential future adaptations to reduce the risk of failure. The good clinical outcomes reported by the patients reaching 1-year follow-up indicate that the medial meniscus prosthesis is a potential solution for patients suffering from postmeniscectomy pain syndrome. LEVEL OF EVIDENCE: Level II.

A lateral extra-articular tenodesis without additional hardware: Surgical technique and biomechanical comparison with an anatomic anterolateral ligament reconstruction in the augmentation of anterior cruciate ligament reconstruction.

BACKGROUND: The aims of this study were to describe a lateral extra-articular tenodesis (LET) using no additional hardware and compare the tibiofemoral kinematics of anterior cruciate ligament (ACL) reconstruction augmented with either the LET or a standard anatomic anterolateral ligament (ALL) reconstruction using intra-tunnel fixation. METHODS: Ten cadaveric knees were mounted on a robotic testing system and underwent a kinematic assessment of anterior tibial translation and internal tibial rotation under a simulated pivot-shift in the following states: ACL-intact, ACL-sectioned, ACL-sectioned/anterolateral complex (ALC)-sectioned, ACL-reconstructed/ALC-sectioned, ACL-reconstructed/ALL-reconstructed, and ACL-reconstructed/LET. For the LET, an iliotibial autograft was passed under the fibular collateral ligament and secured to the femur with the pull sutures of the ACL reconstruction femoral cortical suspensory fixation device, positioned at the distal ridge of Kaplan's fibers. RESULTS: Anterior tibial translation was restored to normal by ACL reconstruction without meaningful benefit of augmentation with LET or ALL. ACL reconstruction restored internal tibial rotation close to normal between 0° and 30°, but increased internal tibial rotation persisted between 45° and 90°. Augmentation of ACL reconstruction with the LET reduced internal rotation close to normal between 45° and 90°, whereas increased internal rotation persisted after ALL reconstruction. CONCLUSION: ACL reconstruction and LET are complementary in controlling tibiofemoral kinematics of knees with a combined ACL and ALC injury: ACL reconstruction restored native tibiofemoral kinematics except for internal rotation at flexion greater than 30°. The increased internal rotation at flexion greater than 30° was restored to normal with an LET, but not with an ALL reconstruction.

Cost-effectiveness of arthroscopic partial meniscectomy versus physical therapy for traumatic meniscal tears in patients aged under 45 years.

Aims: The aim of this study was to evaluate the cost-effectiveness of arthroscopic partial meniscectomy versus physical therapy plus optional delayed arthroscopic partial meniscectomy in young patients aged under 45 years with traumatic meniscal tears. Methods: We conducted a multicentre, open-labelled, randomized controlled trial in patients aged 18 to 45 years, with a recent onset, traumatic, MRI-verified, isolated meniscal tear without knee osteoarthritis. Patients were randomized to arthroscopic partial meniscectomy or standardized physical therapy with an optional delayed arthroscopic partial meniscectomy after three months of follow-up. We performed a cost-utility analysis on the randomization groups to compare both treatments over a 24-month follow-up period. Cost utility was calculated as incremental costs per quality-adjusted life year (QALY) gained of arthroscopic partial meniscectomy compared to physical therapy. Calculations were performed from a healthcare system perspective and a societal perspective. Results: A total of 100 patients were included: 49 were randomized to arthroscopic partial meniscectomy and 51 to physical therapy. In the physical therapy group, 21 patients (41%) received delayed arthroscopic partial meniscectomy during follow-up. Over 24 months, patients in the arthroscopic partial meniscectomy group had a mean 0.005 QALYs lower quality of life (95% confidence interval -0.13 to 0.14). The cost-utility ratio was €-160,000/QALY from the healthcare perspective and €-223,372/QALY from the societal perspective, indicating that arthroscopic partial meniscectomy incurs additional costs without any added health benefit. Conclusion: Arthroscopic partial meniscectomy is arthroscopic partial meniscectomy is unlikely to be cost-effective in treating young patients with isolated traumatic meniscal tears compared to physical therapy as a primary health intervention. Arthroscopic partial meniscectomy leads to a similar quality of life, but higher costs, compared to physical therapy plus optional delayed arthroscopic partial meniscectomy.

A transcriptome atlas of leg muscles from healthy human volunteers reveals molecular and cellular signatures associated with muscle location.

Skeletal muscles support the stability and mobility of the skeleton but differ in biomechanical properties and physiological functions. The intrinsic factors that regulate muscle-specific characteristics are poorly understood. To study these, we constructed a large atlas of RNA-seq profiles from six leg muscles and two locations from one muscle, using biopsies from 20 healthy young males. We identified differential expression patterns and cellular composition across the seven tissues using three bioinformatics approaches confirmed by large-scale newly developed quantitative immune-histology procedures. With all three procedures, the muscle samples clustered into three groups congruent with their anatomical location. Concomitant with genes marking oxidative metabolism, genes marking fast- or slow-twitch myofibers differed between the three groups. The groups of muscles with higher expression of slow-twitch genes were enriched in endothelial cells and showed higher capillary content. In addition, expression profiles of Homeobox (HOX) transcription factors differed between the three groups and were confirmed by spatial RNA hybridization. We created an open-source graphical interface to explore and visualize the leg muscle atlas (https://tabbassidaloii.shinyapps.io/muscleAtlasShinyApp/). Our study reveals the molecular specialization of human leg muscles, and provides a novel resource to study muscle-specific molecular features, which could be linked with (patho)physiological processes.

The role of patient characteristics and the effects of angiogenic therapies on the microvasculature of the meniscus: A systematic review.

BACKGROUND: Considerable interindividual variation in meniscal microvascularization has been reported. The purpose of this review was to identify which patient characteristics affect meniscal microvascularization and provide a structured overview of angiogenic therapies that influence meniscal neovascularization. METHODS: A systematic literature search was undertaken using PubMed, Embase, Web of Science, Cochrane library and Emcare from inception to November 2021. Studies reporting on (1) Patient characteristics that affect meniscal microvascularization, or (2) Therapies that induce neovascularization in meniscal tissue were included. Studies were graded in quality using the Anatomical Quality Assessment (AQUA) tool. The study was registered with PROSPERO(ID:CRD42021242479). RESULTS: Thirteen studies reported on patient characteristics and eleven on angiogenic therapies. The influence of Age, Degenerative knee, Gender, and Race was reported. Age is the most studied factor. The entire meniscus is vascularized around birth. With increasing age, vascularization decreases from the inner to the peripheral margin. Around 11 years, blood vessels are primarily located in the peripheral third of the menisci. There seems to be a further decrease in vascularization with increasing age in adults, yet conflicting literature exists. Degenerative changes of the knee also seem to influence meniscal vascularization, but evidence is limited. Angiogenic therapies to improve meniscal vascularization have only been studied in preclinical setting. The use of synovial flap transplantation, stem cell therapy, vascular endothelial growth factor, and angiogenin has shown promising results. CONCLUSION: To decrease failure rates of meniscal repair, a better understanding of patient-specific vascular anatomy is essential. Translational clinical research is needed to investigate the clinical value of angiogenic therapies.

Arthroscopic partial meniscectomy versus physical therapy for traumatic meniscal tears in a young study population: a randomised controlled trial.

OBJECTIVE: To compare outcomes from arthroscopic partial meniscectomy versus physical therapy in young patients with traumatic meniscal tears. METHODS: We conducted a multicentre, open-labelled, randomised controlled trial in patients aged 18-45 years, with a recent onset, traumatic, MRI-verified, isolated meniscal tear without knee osteoarthritis. Patients were randomised to arthroscopic partial meniscectomy or standardised physical therapy with an optional delayed arthroscopic partial meniscectomy after 3-month follow-up. The primary outcome was the International Knee Documentation Committee (IKDC) score (best 100, worst 0) at 24 months, which measures patients' perception of symptoms, knee function and ability to participate in sports activities. RESULTS: Between 2014 and 2018, 100 patients were included (mean age 35.1 (SD 8.1), 76% male, 34 competitive or elite athletes). Forty-nine were randomised to arthroscopic partial meniscectomy and 51 to physical therapy. In the physical therapy group, 21 patients (41%) received delayed arthroscopic partial meniscectomy during the follow-up period. In both groups, improvement in IKDC scores was clinically relevant during follow-up compared with baseline scores. At 24 months mean (95% CI) IKDC scores were 78 (71 to 84) out of 100 points in the arthroscopic partial meniscectomy group and 78 (71 to 84) in the physical therapy group with a between group difference of 0.1 (95% CI -7.6 to 7.7) points out of 100. CONCLUSIONS: In this trial involving young patients with isolated traumatic meniscal tears, early arthroscopic partial meniscectomy was not superior to a strategy of physical therapy with optional delayed arthroscopic partial meniscectomy at 24-month follow-up. TRIAL REGISTRATION: https://www.trialregister.nl/trials.

ACL reconstruction for all is not cost-effective after acute ACL rupture.

OBJECTIVES: To conduct a cost-utility analysis for two commonly used treatment strategies for patients after ACL rupture; early ACL reconstruction (index) versus rehabilitation plus an optional reconstruction in case of persistent instability (comparator). METHODS: Patients aged between 18 and 65 years of age with a recent ACL rupture (<2 months) were randomised between either an early ACL reconstruction (index) or a rehabilitation plus an optional reconstruction in case of persistent instability (comparator) after 3 months of rehabilitation. A cost-utility analysis was performed to compare both treatments over a 2-year follow-up. Cost-effectiveness was calculated as incremental costs per quality-adjusted life year (QALY) gained, using two perspectives: the healthcare system perspective and societal perspective. The uncertainty for costs and health effects was assessed by means of non-parametric bootstrapping. RESULTS: A total of 167 patients were included in the study, of which 85 were randomised to the early ACL reconstruction (index) group and 82 to the rehabilitation and optional reconstruction group (comparator). From the healthcare perspective it takes 48 460 € and from a societal perspective 78 179 €, to gain a QALY when performing early surgery compared with rehabilitation plus an optional reconstruction. This is unlikely to be cost-effective. CONCLUSION: Routine early ACL reconstruction (index) is not considered cost-effective as compared with rehabilitation plus optional reconstruction for a standard ACL population (comparator) given the maximum willingness to pay of 20 000 €/QALY. Early recognition of the patients that have better outcome of early ACL reconstruction might make rehabilitation and optional reconstruction even more cost-effective.

Intra-operative assessment of the vascularisation of a cross section of the meniscus using near-infrared fluorescence imaging.

PURPOSE: The purpose of this study was to assess whether the vascularisation of the meniscus could be visualised intra-operatively using near-infrared fluorescence (NIRF) imaging with indocyanine green (ICG) in patients undergoing total knee arthroplasty (TKA). METHODS: The anterior horn (i.e., Cooper classification: zones C and D) of the meniscus that was least affected (i.e., least degenerative) was removed during TKA surgery in ten patients to obtain a cross section of the inside of the meniscus. Thereafter, 10 mg of ICG was injected intravenously, and vascularisation of the cross section of the meniscus was assessed using the Quest spectrum NIRF camera system. We calculated the percentage of patients in whom vascularisation was observed intra-operatively using NIRF imaging compared to immunohistochemistry. RESULTS: Meniscal vascularisation using NIRF imaging was observed in six out of eight (75%) patients in whom vascularisation was demonstrated with immunohistochemistry. The median extent of vascularisation was 13% (interquartile range (IQR) 3-28%) using NIRF imaging and 15% (IQR 11-23%) using immunohistochemistry. CONCLUSION: This study shows the potential of NIRF imaging to visualise vascularisation of the meniscus, as vascularisation was observed in six out of eight patients with histologically proven meniscal vascularisation. LEVEL OF EVIDENCE: IV.

[A woman with acute-onset shoulder pain]. / Een vrouw met acuut ontstane schouderklachten.

In this case report we present a 55-year-old female patient with acute-onset shoulder pain. X-rays of the affected shoulder showed clear levels of resorbed calcium in an enlarged subacromial bursa which is typical for the resorptive phase of calcific tendinitis of the rotator cuff.

Differences in Knee Shape between ACL Injured and Non-Injured: A Matched Case-Control Study of 168 Patients.

OBJECTIVE: Anterior cruciate ligament (ACL) injury prevention programs could be more effective if we could select patients at risk for sustaining an ACL rupture. The purpose of this study is to identify radiographic shape variants of the knee between patients with and patients without an ACL rupture. METHODS: We compared the lateral and Rosenberg view X-rays of 168 prospectively followed patients with a ruptured ACL to a control group with intact ACLs, matched for gender, after knee trauma. We used statistical shape modeling software to examine knee shape and find differences in shape variants between both groups. RESULTS: In the Rosenberg view X-rays, we found five shape variants to be significantly different between patients with an ACL rupture and patients with an intact ACL but with knee trauma. Overall, patients who had ruptured their ACL had smaller, flatter intercondylar notches, a lower lateral tibia plateau, a lower medial spike of the eminence, and a smaller tibial eminence compared to control patients. CONCLUSION: Patients with an ACL rupture have smaller intercondylar notches and smaller tibial eminences in comparison to patients with an intact ACL after knee trauma.

Early surgical reconstruction versus rehabilitation with elective delayed reconstruction for patients with anterior cruciate ligament rupture: COMPARE randomised controlled trial.

OBJECTIVE: To assess whether a clinically relevant difference exists in patients' perceptions of symptoms, knee function, and ability to participate in sports over a period of two years after rupture of the anterior cruciate ligament (ACL) between two commonly used treatment regimens. DESIGN: Open labelled, multicentre, parallel randomised controlled trial (COMPARE). SETTING: Six hospitals in the Netherlands, between May 2011 and April 2016. PARTICIPANTS: Patients aged 18 to 65 with an acute rupture of the ACL, recruited from six hospitals. Patients were evaluated at three, six, nine, 12, and 24 months. INTERVENTIONS: 85 patients were randomised to early ACL reconstruction and 82 to rehabilitation followed by optional delayed ACL reconstruction after a three month period (primary non-operative treatment). MAIN OUTCOMES: Patients' perceptions of symptoms, knee function, and ability to participate in sporting activities were assessed with the International Knee Documentation Committee score (optimum score 100) at each time point over 24 months. RESULTS: Between May 2011 and April 2016, 167 patients were enrolled in the study and randomised to one of two treatments (mean age 31.3; 67 (40.%) women), and 163 (98%) completed the trial. In the rehabilitation and optional delayed ACL reconstruction group, 41 (50%) patients underwent reconstruction during follow-up. After 24 months, the early ACL reconstruction group had a significantly better (P=0.026) but not clinically relevant International Knee Documentation Committee score (84.7 v 79.4 (difference between groups 5.3, 95% confidence interval 0.6 to 9.9). After three months of follow-up, the International Knee Documentation Committee score was significantly better (P=0.002) for the rehabilitation and optional delayed ACL reconstruction group (difference between groups -9.3, -14.6 to -4.0). After nine months of follow-up, the difference in the International Knee Documentation Committee score changed in favour of the early ACL reconstruction group. After 12 months, differences between the groups were smaller. In the early ACL reconstruction group, four re-ruptures and three ruptures of the contralateral ACL occurred during follow-up versus two re-ruptures and one rupture of the contralateral ACL in the rehabilitation and optional delayed ACL reconstruction group. CONCLUSIONS: In patients with acute rupture of the ACL, those who underwent early surgical reconstruction, compared with rehabilitation followed by elective surgical reconstruction, had improved perceptions of symptoms, knee function, and ability to participate in sports at the two year follow-up. This finding was significant (P=0.026) but the clinical importance is unclear. Interpretation of the results of the study should consider that 50% of the patients randomised to the rehabilitation group did not need surgical reconstruction. TRIAL REGISTRATION: Netherlands Trial Register NL 2618.

Dutch Guideline on Knee Arthroscopy Part 2: non-meniscus intra-articular knee injury: a multidisciplinary review by the Dutch Orthopaedic Association.

Background and purpose - A guideline committee of medical specialists and a physiotherapist was formed on the initiative of the Dutch Orthopedic Association (NOV) to update the Guideline Arthroscopy of the Knee: Indications and Treatment 2010. This next Guideline was developed between June 2017 and December 2019. In part 1 we focused on the meniscus; this part 2 addresses all other aspects of knee arthroscopy.Methods - The guideline was developed in accordance with the criteria of the AGREE instrument (AGREE II: Appraisal of Guidelines for Research and Evaluation II) with support of a professional methodologist from the Dutch Knowledge Institute of Medical Specialists. The scientific literature was searched and systematically analyzed. Conclusions and recommendations were formulated according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) method. Recommendations were developed considering the balance of benefits and harms, the type and quality of evidence, the values and preferences of the people involved, and the costs.

Dutch Guideline on Knee Arthroscopy Part 1, the meniscus: a multidisciplinary review by the Dutch Orthopaedic Association.

Background and purpose - A guideline committee of medical specialists and a physiotherapist was formed on the initiative of the Dutch Orthopedic Association (NOV) to update the guideline Arthroscopy of the Knee: Indications and Treatment 2010. This next guideline was developed between June 2017 and December 2019. In this Part 1 we focus on the meniscus, in Part 2 on all other aspects of knee arthroscopy.Methods - The guideline was developed in accordance with the criteria of the AGREE instrument (AGREE II: Appraisal of Guidelines for Research and Evaluation II) with support of a professional methodologist from the Dutch Knowledge Institute of Medical Specialists. The scientific literature was searched and systematically analyzed. Conclusions and recommendations were formulated according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) method. Recommendations were developed considering the balance of benefits and harms, the type and quality of evidence, the values and preferences of the people involved, and the costs.

Functional Outcomes of Arthroscopic Partial Meniscectomy Versus Physical Therapy for Degenerative Meniscal Tears Using a Patient-Specific Score: A Randomized Controlled Trial.

BACKGROUND: It is unknown whether the treatment effects of partial meniscectomy and physical therapy differ when focusing on activities most valued by patients with degenerative meniscal tears. PURPOSE: To compare partial meniscectomy with physical therapy in patients with a degenerative meniscal tear, focusing on patients' most important functional limitations as the outcome. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: This study is part of the Cost-effectiveness of Early Surgery versus Conservative Treatment with Optional Delayed Meniscectomy for Patients over 45 years with non-obstructive meniscal tears (ESCAPE) trial, a multicenter noninferiority randomized controlled trial conducted in 9 orthopaedic hospital departments in the Netherlands. The ESCAPE trial included 321 patients aged between 45 and 70 years with a symptomatic, magnetic resonance imaging-confirmed meniscal tear. Exclusion criteria were severe osteoarthritis, body mass index >35 kg/m2, locking of the knee, and prior knee surgery or knee instability due to an anterior or posterior cruciate ligament rupture. This study compared partial meniscectomy with physical therapy consisting of a supervised incremental exercise protocol of 16 sessions over 8 weeks. The main outcome measure was the Dutch-language equivalent of the Patient-Specific Functional Scale (PSFS), a secondary outcome measure of the ESCAPE trial. We used crude and adjusted linear mixed-model analyses to reveal the between-group differences over 24 months. We calculated the minimal important change for the PSFS using an anchor-based method. RESULTS: After 24 months, 286 patients completed the follow-up. The partial meniscectomy group (n = 139) improved on the PSFS by a mean of 4.8 ± 2.6 points (from 6.8 ± 1.9 to 2.0 ± 2.2), and the physical therapy group (n = 147) improved by a mean of 4.0 ± 3.1 points (from 6.7 ± 2.0 to 2.7 ± 2.5). The crude overall between-group difference showed a -0.6-point difference (95% CI, -1.0 to -0.2; P = .004) in favor of the partial meniscectomy group. This improvement was statistically significant but not clinically meaningful, as the calculated minimal important change was 2.5 points on an 11-point scale. CONCLUSION: Both interventions were associated with a clinically meaningful improvement regarding patients' most important functional limitations. Although partial meniscectomy was associated with a statistically larger improvement at some follow-up time points, the difference compared with physical therapy was small and clinically not meaningful at any follow-up time point. REGISTRATION: NCT01850719 (ClinicalTrials.gov identifier) and NTR3908 (the Netherlands Trial Register).

Meniscal allograft transplantation in The Netherlands: long-term survival, patient-reported outcomes, and their association with preoperative complaints and interventions.

PURPOSE: Evaluation of survival of meniscal allograft transplantation (MAT) and postoperative patient-reported outcome (PRO), and their association with prior interventions of the knee. METHODS: A prospective consecutive study of 109 consecutive patients who had an arthroscopic meniscal allograft transplantation (MAT) between 1999 and 2017 by a single surgeon. Patients were assessed with KOOS scores, preoperative and after a minimal follow-up of 2 years. Furthermore, two anchor questions (whether expectations were met and overall satisfaction, on a five-point Likert scale) were asked. Additionally, prior interventions to MAT were evaluated. RESULTS: Prior to MAT, patients had undergone an average of 2.8 (range 1-14) of surgical procedures of the knee. Overall, mean allograft survival was 16.1 years (95% CI 14.8-17.5 years). Higher age at surgery was associated with lower MAT survival: hazard ratio for MAT failure was 1.19 per year increase (95% CI 1.04 to 1.36, p = 0.009). At 4.5 years (IQR, 2-9) of follow-up, all KOOS score were still improved compared to baseline. Age below 35 years, simultaneous anterior cruciate ligament reconstruction and number of knee surgeries before MAT were associated with lower KOOS scores. Overall patient expectations and overall satisfaction after MAT were not associated with preoperative patient characteristics nor with the number or kind of preoperative interventions. CONCLUSION: Meniscal allograft transplantation has a good overall survival with a clinically relevant improvement. Both meniscal allograft survival and PRO were associated with age. PRO was lower in patients younger than 35 years at time of MAT and meniscal allograft survival was worse in patients older than 50 years. PRO was associated with preoperative patient characteristics and number of surgical procedures prior to MAT. All patients reported improved postoperative satisfaction and met expectations after MAT, both independent of the preoperative history of knee interventions. LEVEL OF EVIDENCE: Level III. Trial registration Medical ethical review board (METC) number: 17-104 (7 August 2017). Dutch Trial Register (NTR) number: NTR6630 (4 July 2017).

[Anterior cruciate ligament rupture in children: A growing problem]. / Voorste-kruisbandruptuur bij kinderen.

The number of knee injuries in young children has risen sharply in recent years, due to more intensive participation in sporting activities by children at an increasingly lower age. This has led to more anterior cruciate ligament (ACL) ruptures. An ACL rupture has major consequences for the young athlete, but diagnosing this injury in a child can be difficult due to pain and anxiety. The criteria for appropriate treatment of an ACL rupture are not always clear for the child, the doctor, the parents and the sporting coach. Here we describe the diagnosis and possible treatment options for an ACL rupture in children based on three cases. We conclude that the incidence of ACL ruptures in children is a growing problem. There is a challenge for sports associations, sports clubs, trainers and parents to build in prevention programmes during weekly training sessions. The considerations to be taken into account concerning diagnosis and different treatment options show, once again, that children cannot simply be considered as small adults.

Joint needle aspiration compared to tissue samples in septic arthritis of the native knee.

Culture of the causative infectious agent is the only definitive method of diagnosing septic arthritis and can be identified by culture of synovial fluid (SF) or by tissue cultures (TC) obtained at surgery. The aim of this study is to compare the cultures of joint needle aspiration (JNA) with tissue cultures obtained at surgery. 52 patients treated for a suspicion of a septic arthritis of the native knee were retrospectively reviewed. In 84% tissue cultures were equal to joint needle aspiration. Median Gächter classification was 1.0 (range 1-3). 60% of the patients underwent multiple procedures. All patients were successfully treated with an average of 2.0 (range 1-6) arthroscopies. Our results showed that if a patient with a clinical suspicion of septic arthritis is treated, starting antibiotic therapy prior to surgery can be considered, but only after joint needle aspiration to obtain samples for bacteriologic culture. Arthroscopic surgery must be the treatment of choice in Gächter stage 1 to 3, although it might be necessary to perform multiple procedures.

The Occurrence of Meniscal and Chondral Injury in Two-Stage Revision Anterior Cruciate Ligament Reconstruction: A Consecutive Case Series.

Two-stage revision anterior cruciate ligament (ACL) reconstruction is an effective way to revise suboptimal tunnel-placement allowing for proper graft fixation. However, prolonged increased laxity of the knee may increase the risk of meniscal or chondral injury. It was hypothesized that no additional meniscal or chondral lesions occur in between the two stages of the two-stage revision ACL reconstruction. In this retrospective study, 42 patients undergoing a two-stage revision ACL reconstruction were included. Surgical notes for both stages were screened for meniscal and chondral status, interventions to any concurrent injury, surgery dates, along with basic patient characteristics. In 4 of the 42 patients, a new meniscal tear occurred in between the two stages, of which three required partial meniscectomy during the second stage of the ACL revision. One patient experienced a new small degenerative tear that did not require intervention. Two out of the four menisci that were repaired during the first stage had failed and required partial meniscectomy. No significant difference was found in the time between the two stages with respect to the occurrence of meniscal tears. No significant differences in chondral status were found. In conclusion, approximately 10% of patients developed a new meniscal tear and no difference in macroscopic chondral injury was observed between the first and second stages.

The Medial Patellofemoral Ligament Is a Dynamic and Anisometric Structure: An In Vivo Study on Length Changes and Isometry.

BACKGROUND: Medial patellofemoral ligament (MPFL) reconstruction is associated with a high rate of complications, including recurrent instability and persistent knee pain. Technical errors are among the primary causes of these complications. Understanding the effect of adjusting patellofemoral attachments on length change patterns may help surgeons to optimize graft placement during MPFL reconstruction and to reduce graft failure rates. PURPOSE: To determine the in vivo length changes of the MPFL during dynamic, weightbearing motion and to map the isometry of the 3-dimensional wrapping paths from various attachments on the medial femoral epicondyle to the patella. STUDY DESIGN: Descriptive laboratory study. METHODS: Fifteen healthy participants were studied with a combined computed tomography and biplane fluoroscopic imaging technique during a lunge motion (full extension to ~110° of flexion). On the medial femoral epicondyle, 185 attachments were projected, including the anatomic MPFL footprint, which was divided into 5 attachments (central, proximal, distal, posterior, and anterior). The patellar MPFL area was divided into 3 possible attachments (proximal, central, and distal). The length changes of the shortest 3-dimensional wrapping paths of the various patellofemoral combinations were subsequently measured and mapped. RESULTS: For the 3 patellar attachments, the most isometric attachment, with an approximate 4% length change, was located posterior and proximal to the anatomic femoral MPFL attachment, close to the adductor tubercle. Attachments proximal and anterior to the isometric area resulted in increasing lengths with increasing knee flexion, whereas distal and posterior attachments caused decreasing lengths with increasing knee flexion. The anatomic MPFL was tightest in extension, decreased in length until approximately 30° of flexion, and then stayed near isometric for the remainder of the motion. Changing both the femoral and patellar attachments significantly affected the length changes of the anatomic MPFL ( P < .001 for both). CONCLUSION: The most isometric location for MPFL reconstruction was posterior and proximal to the anatomic femoral MPFL attachment. The anatomic MPFL is a dynamic, anisometric structure that was tight in extension and early flexion and near isometric beyond 30° of flexion. CLINICAL RELEVANCE: Proximal and anterior MPFL tunnel positioning should be avoided, and the importance of anatomic MPFL reconstruction is underscored with the results found in this study.

Anatomic is better than isometric posterior cruciate ligament tunnel placement based upon in vivo simulation.

PURPOSE: To elucidate the effects of various tibial and femoral attachment locations on the theoretical length changes and isometry of PCL grafts in healthy knees during in vivo weightbearing motion. METHODS: The intact knees of 14 patients were imaged using a combined magnetic resonance and dual fluoroscopic imaging technique while the patient performed a quasi-static lunge (0°-120° of flexion). The theoretical end-to-end distances of the 3-dimensional wrapping paths between 165 femoral attachments, including the anatomic anterolateral bundle (ALB), central attachment and posteromedial bundle (PMB) of the PCL, connected to an anterolateral, central, and posteromedial tibial attachment were simulated and measured. A descriptive heatmap was created to demonstrate the length changes on the medial condyle and formal comparisons were made between the length changes of the anatomic PCL and most isometric grafts. RESULTS: The most isometric graft, with approximately 3% length change between 0° and 120° of flexion, was located proximal to the anatomic femoral PCL attachments. Grafts with femoral attachments proximal to the isometric zone decreased in length with increasing flexion angles, whereas grafts with more distal attachments increased in length with increasing flexion angles. The ALB and central single-bundle graft demonstrated a significant elongation from 0° to 120° of flexion (p < 0.001). The PMB decreased in length between 0° and 60° of flexion after which the bundle increased in length to its maximum length at 120° (p < 0.001). No significant differences in length changes were found between either the ALB or PMB and the central graft, and between the ALB and PMB at flexion angles ≥ 60° (n.s.). CONCLUSIONS: The most isometric attachment was proximal to the anatomic PCL footprint and resulted in non-physiological length changes. Moving the femoral attachment locations of the PCL significantly affected length change patterns, whereas moving the tibia locations did not. The importance of anatomically positioned (i.e., distal to the isometric area) femoral PCL reconstruction locations to replicate physiological length changes is highlighted. These data can be used to optimize tunnel positioning in either single- or double-bundle and primary or revision PCL reconstruction cases. LEVEL OF EVIDENCE: IV.