Nonanatomical femoral tunnel positioning in isolated MPFL reconstruction is not associated with an increased risk of patellofemoral osteoarthritis after a minimum follow-up of 10 years.

PURPOSE: The association between the prevalence of patellofemoral arthritis (PFA) and femoral tunnel positioning following isolated medial patellofemoral ligament reconstruction (MPFLr) has not been well described. The aim of this study was to analyse the relationship between femoral tunnel positioning and the prevalence of PFA. METHODS: This was a single-centre study of patients undergoing an isolated MPFLr between 2006 and 2011 with a minimum of 10 years of follow-up. Outcomes assessed were the presence of PFA on radiographs, recurrence of instability requiring revision surgery and patient-reported outcomes, including Kujala, Tegner and IKDC scores. Tunnel positioning was assessed on postoperative radiographs using two radiographic methods: Schöttle's point and the grid method to localise the femoral tunnel. Patients were grouped based on tunnel positioning and compared. RESULTS: Fifty patients were analysed at a mean follow-up of 12.4 years. Thirty-three patients (66%) had a femoral tunnel position within 7 mm of Schöttle's point and 39 (78%) within the anatomic quadrant, with the most common location according to the grid method in D4 (28%) and E4 (26%), respectively. Thirty-seven patients (74%) had a satisfactory (>80 versus <80) Kujala score at long-term follow-up. None of the examined tunnel assessment methods demonstrated a significant relationship with Tegner, Kujala or International Knee Documentation Committee scores. Patients with a femoral tunnel position >7 mm outside Schöttle's point or were considered to be in a nonanatomic position were not significantly more likely to result in unsatisfactory Kujala scores at the last follow-up. Tunnel positioning and the other tested parameters were not found to be significantly associated with the development of PFA. CONCLUSION: No correlation between femoral tunnel position and risk of PFA or poor outcomes was observed in patients undergoing isolated MPFLr at long-term follow-up. The impact of femoral tunnel placement on long-term outcomes in patients with PFI may be less significant than originally considered. LEVEL OF EVIDENCE: Level IV.

Medium-term clinical and radiographic outcomes of a cementless prosthesis with a 140° neck-shaft angle in reverse total shoulder arthroplasty.

BACKGROUND: The design of humeral implants has evolved from the initial Grammont design, notably regarding the neck-shaft angle (NSA) and through the use of cementless prostheses. Stress shielding was frequently reported with cementless implants, the 2 main risk factors being humeral stem misalignment and high filling ratios. Our hypothesis was that standard length cementless stems with an NSA of 140° would facilitate good alignment with moderate filling ratios, thereby limiting stress shielding and ensuring good clinical outcomes. METHODS: A single-center retrospective study was conducted of patients who underwent reverse total shoulder arthroplasty between January 2015 and August 2017, with at least 2 years' follow-up. Clinical evaluations included range of motion measurements and Constant and subjective shoulder values scores. Frontal alignment was assessed in terms of the angle (α) between axes of the stem and of the humerus. Filling ratios were measured in the metaphysis of the humerus, in the diaphysis, and at the distal end of the stem and considered excessive above 0.7. Stress shielding was evidenced radiographically by the observation of medial cortical narrowing, medial metaphysis thinning, lateral metaphysis thinning or under-the-baseplate osteolysis. RESULTS: Eighty-two shoulders were included and 70 had radiographic follow-up data available. The mean patient age was 78 years and 63/81 patients (78%) were female. The mean follow-up time was 39 ± 7 months. The mean α angle was 1.4° ± 0.9° and was less than 5° in all cases. The mean metaphyseal, diaphyseal, and distal filling ratios were 0.61 ± 0.06, 0.70 ± 0.08, and 0.64 ± 0.09, respectively. The mean Constant score improved from 28 ± 11 preoperatively to 64 ± 14 at last follow-up. The mean subjective shoulder values score at last follow-up was 81 ± 12. Seventy-nine percent of patients (55/70) had at least 1 form of stress-shielding related, which were not associated with clinical outcomes, apart from lateral metaphysis thinning, which was associated with lower active anterior elevation (mean, 106° ± 30° vs. 126° ± 28°; P = .01) and lower Constant scores (mean, 56 ± 17 vs. 65 ± 14; P = .06). CONCLUSION: The use of cementless reverse shoulder prostheses with a NSA of 140° was associated with good clinical outcomes at 2 years' follow-up. The prosthesis stem was correctly aligned with the humeral axis and the filling ratios were <0.7 in all cases. Stress-shielding was common but, apart from lateral metaphysis thinning, this had no impact on clinical outcomes.

Risk of suprascapular nerve injury in open Trillat procedure: an anatomical study.

PURPOSE: The open Trillat Procedure described to treat recurrent shoulder instability, has a renewed interest with the advent of arthroscopy. The suprascapular nerve (SSN) is theoretically at risk during the drilling of the scapula near the spinoglenoid notch. The purpose of this study was to assess the relationship between the screw securing the coracoid transfer and the SSN during open Trillat Procedure and define a safe zone for the SSN. METHODS: In this anatomical study, an open Trillat Procedure was performed on ten shoulders specimens. The coracoid was fixed by a screw after partial osteotomy and antero-posterior drilling of the scapular neck. The SSN was dissected with identification of the screw. We measured the distances SSN-screw (distance 1) and SSN-glenoid rim (distance 2). In axial plane, we measured the angles between the glenoid plane and the screw (α angle) and between the glenoid plane and the SSN (ß angle). RESULTS: The mean distance SSN-screw was 8.8 mm +/-5.4 (0-15). Mean α angle was 11°+/-2.4 (8-15). Mean ß angle was 22°+/-6.7 (12-30). No macroscopic lesion of the SSN was recorded but in 20% (2 cases), the screw was in contact with the nerve. In both cases, the ß angle was measured at 12°. CONCLUSION: During the open Trillat Procedure, the SSN can be injured due to its anatomical location. Placement of the screw should be within 10° of the glenoid plane to minimize the risk of SSN injury and could require the use of a specific guide or arthroscopic-assisted surgery.

Similar survival rate but lower functional outcomes following TKA in the elderly people compared to younger patients: analysis of a posterior stabilised implant with minimum 5-year follow-up.

BACKGROUND: Literature regarding outcomes in patients over 80 years old after total knee arthroplasty (TKA) is inconsistent. We aimed to compare implant survivorship and functional outcomes between elderly patients (≥ 80 years) and younger patients (< 80 years) following TKA, using a single modern posterior-stabilized (PS) prosthetic design. METHODS: This is a retrospective cohort study of 80 patients over 80 years old who underwent TKA between January 2015 and December 2016, who were compared with younger patients (60-75 years old) operated during the same period. Patients were matched with a ratio of 1:3 based on logistic regression analysis of gender and body mass index. All patients received the same cemented PS prosthesis with a fixed bearing polyethylene insert, with or without patellar resurfacing. Implant survival and patient-reported outcome measurements were compared between the two groups. At last follow-up, data were available for 41 knees in the elderly group (including 17 patients who died before 5-year follow-up) and 123 knees in the younger group. RESULTS: Functional results were better at final follow-up in the group < 80 years with a significantly higher Knee Society Function Subscore (88.6 ± 16.9 vs 79.4 ± 22.1, p < 0.01), but no significant differences in Knee Subscore and global Knee Society Score (p > 0.05), nor regarding maximum flexion (121° ± 12 and 117° ± 13, p = 0.08). The implant survivorship was 100.0% after a mean 64.4-month follow-up (range 60-78), without revision requiring removal of the implant in any group. The survival rate without any reoperation was 97.6% (95% CI 93.0-100.0) in the elderly group and 95.9% (95% CI 92.5-99.5) in the younger group (p = 0.64). CONCLUSION: At a minimum of 5-year follow-up, there was no revision surgery and a very low rate of complications requiring reoperations both in the group over 80 years of age and in the younger population, with the use of a PS prosthesis. The functional results were slightly lower for elderly patients and correlate with the lower functional demands of this population. The indication for TKA, especially with a PS implant, may be encouraged in appropriately selected elderly patients. LEVEL OF EVIDENCE: III (retrospective cohort study).

Delaying ACL reconstruction is associated with increased rates of medial meniscal tear.

PURPOSE: The aim of this study was to evaluate the relationship between the time from injury to ACL reconstruction (ACLR) and the rate as well as repairability of meniscal tears. Secondary aims were to evaluate the relationship between meniscal injury and Tegner Activity Scale, age, BMI, and gender. METHODS: Between 2012 and 2022, 1,840 consecutive ACLRs were performed. A total of 1,317 ACLRs were included with a mean patient age of 31.2 years ± 10.5 [16-60]. Meniscal tear was assessed during arthroscopy using the ISAKOS classification. Time from injury to ACLR, Tegner Activity Scale, age, BMI and gender were analysed in uni- and then in multivariate analyses. Patients were divided into four groups according to the time from injury to surgery: < 3 months (427; 32%), 3-6 months (388; 29%), 6-12 months (248; 19%) and > 12 months (254; 19%). RESULTS: Delaying ACLR > 12 months significantly increased the rate of medial meniscal (MM) injury (OR 1.14; p < 0.001). No correlation was found between a 3- or 6-month time from injury to surgery and MM tear. Performing ACLR > 3, 6, or 12 months after injury did not significantly increase the rate of lateral meniscal (LM) injury. Increasing Tegner activity scale was significantly associated with a lower rate of MM injury (OR 0.90; p = 0.020). An age > 30 years (OR 1.07; p = 0.025) and male gender (OR 1.13; p < 0.0001) was also associated with an increased rate of MM injury. Age > 30 years decreased the rate of MM repair (OR 0.85; p < 0.001). Male gender increased the rate of LM tear (OR 1.10; p = 0.001). CONCLUSION: Performing ACLR more than 12 months after injury was associated with increased rates of MM injury but not with lower rates of repairable lesions. An increased pre-injury Tegner activity score was associated with a decreased rate of MM tear. Age > 30 years was associated with an increased rate of MM tear with concomitant ACL injury and a decreased rate of repairability of MM tear. ACLR should be performed within 12 months from injury to prevent from the risk of MM injury. LEVEL OF EVIDENCE: Level III.

How long does image based robotic total knee arthroplasty take during the learning phase? Analysis of the key steps from the first fifty cases.

INTRODUCTION: Robotically assisted total knee arthroplasty (RA-TKA) is an emerging surgical tool. The purpose of this study was to analyze the length of time taken to perform the key steps of a RA-TKA for a surgeon and centre new to the MAKO robotic system. METHOD: This was a prospective cohort study of the first 50 patients undergoing TKA using a robotic platform (Mako, Stryker, Kalamazoo, MI, USA) performed by a single surgeon. Each key surgical step was recorded. The first 50 patients were chronologically allocated into five groups of ten and compared. RESULTS: Mean operation length was 59.4 ± 7.4 min with significant improvement after 30 cases. A significant effect on certain steps of the surgery also occurred over 50 cases: after 30 cases for pre-operative planning (3.8 min in group 1 versus 1.2 min in group 4, p < 0.005), ten cases for registration time (5.2 min in group 1 versus 3.8 in group 2, p = 0.039) and ten cases for tibial cutting time (1.6 min in group 1 versus 1.3 in group 2, p < 0.005). Nurse setup, femur cutting, and intraoperative planning did not demonstrate a significant improvement in time over 50 cases. CONCLUSION: A significant decrease in total operating length occurred after the 30th case. Anatomical registration and tibial cutting time demonstrated the largest improvements. MAKO image-based robotically assisted TKA is not a time-intensive intervention for both the surgeon and scrub nursing staff, and significant improvements in total surgical time occurs early in the learning phase.

Kinematic alignment fails to achieve balancing in 50% of varus knees and resects more bone compared to functional alignment.

PURPOSE: Evidence is emerging that tibio-femoral compartmental balancing is related to clinical outcomes after total knee arthroplasty (TKA). The purpose of this study was to assess if kinematic alignment (KA) delivered a balanced knee in flexion and extension after TKA on varus deformity, compared to functional alignment (FA). METHODS: This single-centre retrospective cohort study assessed 110 consecutive TKAs performed with an image-based robotic system for pre-operative varus deformity. The ligament balancing in the medial and lateral femorotibial compartments was assessed intra-operatively with a robotic system to evaluate if a KA plan would deliver a balanced knee. Balance was considered achieved if tibio-femoral compartments (medial/lateral) were equal to or less than 1.5 mm, or if the estimated final gap position more than 2 mm from the global implant thickness (17 mm). Implant positioning was modified within limits previously defined for a FA philosophy to achieve balancing. Resection thickness and implant positioning were compared with the KA plan and after the FA adjustments; and also, between the patients with a final balanced knee in extension and at 90° of flexion. RESULTS: A total of 102 patients were eligible for final analysis. Mean age was 67.3 ± 8.2 years, average BMI was 29.1 ± 5.2 kg/m2, mean pre-operative coronal alignment was 174.0° ± 3.3° and sagittal alignment 3.4° ± 5.9°. Mean post-operative coronal alignment was 177.7° ± 1.0° and sagittal alignment 0.8° ± 1.9°. A KA plan delivered medial-lateral tibio-femoral compartment balancing in 67 cases (65.7%) for the extension gap and in 50 cases (49.1%) for the flexion gap. All measured bone resection depths were significantly less for FA compared to KA. To achieve balancing targets, final femoral component position was more externally rotated relative to the posterior condylar axis, (0.5° with KA compared to 1.7° with FA (p < 0.0001), and the tibia in more varus (3.0° KA vs. 3.5° FA p = 0.0024). Only one soft tissue release was required. CONCLUSION: KA failed to deliver a balanced TKA in more than 50% of cases, especially regarding the flexion gap. Consideration of soft tissue laxity led to significantly less bone resection, with more externally rotated femoral component and more varus tibial component.

Does healing of both greater and lesser tuberosities improve functional outcome after reverse shoulder arthroplasty for fracture? A retrospective study of twenty-eight cases with a computed tomography scan at a minimum of one-year follow-up.

PURPOSE: Reverse shoulder arthroplasty (RSA) is often indicated in elderly patients with displaced proximal humerus fractures (PHF). The rate of greater tuberosity (GT) healing varies from 37 to 90% in this population. The aim of this study was to assess greater and lesser tuberosity (LT) fixation and healing on CT scan after RSA for PHF. Our hypothesis was that both GT and LT healing leads to better functional results after RSA for fracture. METHODS: Our retrospective cohort consisted of 28 patients treated with an RSA for a four-part PHF during the inclusion period. The mean age at surgery was 77 years. Clinical examination and CT scan were performed at a minimum one year follow-up to assess tuberosity position and healing. RESULTS: The GT healed in 22 patients (78.5%), the LT in 24 patients (87.5%) and both tuberosities were healed in 20 patients (71.5%). Constant score was significantly improved with GT, LT and both tuberosity healing (p = 0.05, p = 0.04 and p = 0.02 respectively). Motion in anterior elevation was improved with GT and both tuberosity healing (p = 0.01 and p = 0.04 respectively). Motion in external rotation was improved with GT and both tuberosity healing (p = 0.01 and p = 0.02 respectively). CONCLUSION: GT and LT healing was associated with better functional results and active motion. Anatomical reduction and consolidation of both tuberosities is beneficial with a cumulative effect for functional recovery.

Highly crosslinked polyethylene: a safe alternative to conventional polyethylene for dual mobility cup mobile component. A biomechanical validation.

PURPOSE: Dual mobility cup (DMC) consists of a cobalt-chromium (CoCr) alloy cup articulated with a polyethylene (PE) mobile component capturing the femoral head in force using a snap-fit technique. This biomechanical study was the first to evaluate and compare the generation of cracks in the retentive area of DMC mobile components made of highly crosslinked PE (XLPE) or conventional ultra-high molecular weight PE (UHMWPE). METHODS: Eighty mobile components designed for a 52-mm diameter Symbol® DMC (Dedienne Santé, Mauguio, France) and a 28-mm diameter femoral head were analyzed. Four groups of 20 mobile components were constituted according to the PE material: raw UHMWPE, sterilized UHMWPE, annealed XLPE and remelted XLPE. Ten mobile components in each group were impacted with a 28-mm diameter CoCr femoral head using a snap-fit technique. The occurrence, location and area of the cracks in the retentive area were investigated using micro-CT (Skyscan 1176®, Bruker, Aarsellar, Belgium) with a 35 µm nominal isotropic voxel size by two observers blinded to the PE material and impaction or not of the mobile components. RESULTS: Compared to conventional UHMWPE, the femoral head snap-fit did not generate more or wider cracks in the retentive area of annealed or remelted XLPE mobile components. CONCLUSION: This biomechanical study suggests that XLPE in DMC could be a safe alternative to conventional UHMWPE regarding the generation of cracks in the retentive area related to the femoral head snap-fit.

Equivalent results of medial and lateral parapatellar approach for total knee arthroplasty in mild valgus deformities.

PURPOSE: When performing total knee arthroplasty (TKA) in valgus knee deformities, a medial or lateral parapatellar approach can be performed, but the lateral approach is often considered technically more difficult. The purpose of this study was to compare intra-operative, early clinical and radiological outcomes of medial and lateral parapatellar approaches for TKA in the setting of moderate knee valgus (<10°). METHODS: We prospectively analysed 424 knees with pre-operative valgus deformity between 3° and 10° that underwent TKA over an 18-year period; 109 were treated with a medial approach and 315 with a lateral approach. Intra- and post-operative outcomes and complication rates after a minimum follow-up of one year were compared. RESULTS: Tourniquet (p = 0.25) and surgical (p = 0.62) time were similar between groups. The popliteus tendon was released more frequently in the medial-approach group (p = 0.04), while the iliotibial band was released more frequently in the lateral-approach group (p < 0.001). A tibial tuberosity osteotomy was performed more frequently in the lateral- than medial-approach group (p = 0.003). No significant differences in limb alignment (p = 0.78), or Knee Society Score (KSS) knee (p = 0.32) and function (p = 0.47) results were noted based on surgical approach, and complication rates were similar between groups (p = 0.53). CONCLUSIONS: Lateral parapatellar approach is a safe and effective surgical technique for performing TKA in moderately valgus knees. These equivalent early results are encouraging for systematic use of the lateral approach in moderately valgus knees.

Stress shielding in stemmed reverse shoulder arthroplasty: an updated review.

BACKGROUND: Reverse shoulder arthroplasty (RSA) is popular for the treatment of degenerative glenohumeral joint disease. Bone remodeling around the humeral stem related to stress shielding (SS) has been described. This review focuses on the specific radiological characteristics, risk factors, and clinical consequences of SS in RSA. METHODS: A meticulous review was conducted of articles published between 2013 and 2023. Data on the definition, risk factors, and clinical impact of stress shielding were recorded. RESULTS: Twenty-eight studies describing 2691 patients who had undergone RSA were included. The mean age of patients ranged from 63 to 80 years with mean follow-up periods of 12 months to 9.6 years. The prevalence of SS reached up to 39% at a 2-year follow-up. Females and elderly are typically at higher risk due to osteopenia. SS was more frequent with the use of long stems(>100 mm) compared to short stems(<100 mm). Stem design, onlay or inlay, and neck-shaft-angle did not influence SS. Frontal misalignment and a high filling ratio are riskfactors for SS. Biological factors also contribute to SS, associated with scapular notching. No correlation was found between SS and clinical outcomes. CONCLUSIONS: SS is common in patients with cementless implants after RSA, especially in female and elderly patients. It can be limited by implanting stems with a low diaphyseal filling-ratio, in correct coronal alignment. Risk factors for polyethylene debris, primarily scapular notching, should be avoided. The authors found no clinical consequences of stress shielding, but longer-term follow-up studies are required to confirm these findings.

What is the best fixation method in medial patellofemoral ligament reconstruction? A biomechanical comparison of common methods for femoral graft attachment.

INTRODUCTION: A variety of techniques have been described for femoral fixation in medial patellofemoral ligament reconstruction (MPFLr). The aim of this study was to compare the biomechanical performance of the most used methods for graft fixation in the femur using human cadaveric tissue. We wondered what is the best fixation method for femoral fixation in MPFL reconstruction? HYPOTHESIS: A suspensory fixation device provides the best femoral fixation. MATERIAL AND METHOD: Twenty cadaveric knees were tested. Four femoral fixation methods were compared (5 knees per group): interference fixation with a Biosure© RG 5 mm and a 7 mm, suture anchor (Healicoil Regenesorb 4.75 mm ©) and suspensory fixation with the Ultrabutton©. The testing was divided in preconditioning, cyclic loading and load to failure. Load to failure, elongation, stiffness and mode of failure were recorded and compared. RESULTS: The Ultrabutton© had the highest mean ultimate load (427 ± 215 N (p = 0.5)), followed by Healicoil anchor © (308 ± 44 N (p > 0.05)) and the interference screw of 7 mm (255 ± 170 N (p > 0.05)). Mean stiffness was similar in the Ultrabutton© and 4.75 mm. Healicoil anchor © groups (111 ± 21 N/mm and 119 ± 20 N/mm respectively), and lowest in 7 mm Biosure© screw fixation group (90 ± 5 N/mm). The Biosure© 5 mm RG screw presented 100% of premature rupture because of tendon slippage. The Ultrabutton© presented the lowest premature rupture (40%). DISCUSSION: A suspensory fixation for the femur had the lowest number of graft failures and highest load to failure. This study has implications for surgeons' choice of graft fixation in MPFLr. It is the first study to test the most commonly femoral used fixation methods, allowing direct comparisons between each method.

No clinical difference at mid-term follow-up between TiN-coated versus uncoated cemented mobile-bearing total knee arthroplasty: a matched cohort study.

INTRODUCTION: Nitride-based ceramic coating was introduced into surgical implants to improve hardness, reduce abrasion, and decrease the risk of metal-induced adverse reactions, especially for patients with suspected or identified metal hypersensitivity. The study aimed to evaluate the effectiveness and safety of a titanium nitride (TiN) coated prosthesis with a mobile bearing design. METHODS: This was a retrospective matched-cohort study from a single center, comparing clinical outcomes between patients receiving either a TiN-coated versus an uncoated cobalt-chromium-molybdenum (CoCrMo) prostheses for primary total knee replacement. Seventeen patients received the TiN prosthesis between 2015 and 2019. These were matched 1:2 with patients receiving uncoated mobile-bearing knee prostheses with the same design manufacturer. RESULTS: Fourteen patients in the TiN group had complete 5-year follow-up data and were compared with 34 patients from the CoCrMo group. The Knee Society Score was 170.6 ± 28.0 (Function subscore 83.7 ± 17.5 and Knee subscore 86.9 ± 13.8) in the TiN group and 180.7 ± 49.4 (Function subscore 87.5 ± 14.3 and Knee subscore 93.2 ± 9.6) in CoCrMo group, with no statistically significant difference (p = 0.19). One patient underwent a revision for instability requiring the removal of the implant in the TiN group and none in the CoCrMo group. The survival rates were 92.9% (CI95% 77.3-100.0) and 100.0% in the TiN group and CoCrMo group respectively (p = 1.0). DISCUSSION: TiN-coated TKA with mobile bearing resulted in satisfactory clinical outcomes, and a low revision rate, and there was no complication related to the coated implant. The use of TiN-coated prostheses in case of confirmed or suspected metal allergy provides satisfactory short-term clinic outcomes.

Functional Alignment Philosophy in Total Knee Arthroplasty-Rationale and Technique for the Valgus Morphotype Using an Image Based Robotic Platform and Individualized Planning.

Functional alignment (FA) is a novel philosophy to deliver a total knee arthroplasty (TKA) that respects individual bony and soft tissue phenotypes within defined limitations. The purpose of this paper is to describe the rationale and technique of FA in the valgus morphotype with the use of an image-based robotic-platform. For the valgus phenotype the principles are personalized pre-operative planning, reconstitution of native coronal alignment without residual varus or valgus of more than 3°, restoration of dynamic sagittal alignment within 5° of neutral, implant sizing to match anatomy, and achievement of defined soft tissue laxity in extension and flexion through implant manipulation within the defined boundaries. An individualized plan is created from pre-operative imaging. Next, a reproducible and quantifiable assessment of soft tissue laxity is performed in extension and flexion. Implant positioning is then manipulated in all three planes if necessary to achieve target gap measurements and a final limb position within a defined coronal and sagittal range. FA is a novel TKA technique that aims to restore constitutional bony alignment and balance the laxity of the soft tissues by placing and sizing implants in a manner that respects variations in individual anatomy and soft tissues within defined limits.

Delaying anterior cruciate ligament reconstruction increases the rate and severity of medial chondral injuries.

Aims: The aim of this study was to evaluate the association between chondral injury and interval from anterior cruciate ligament (ACL) tear to surgical reconstruction (ACLr). Methods: Between January 2012 and January 2022, 1,840 consecutive ACLrs were performed and included in a single-centre retrospective cohort. Exclusion criteria were partial tears, multiligament knee injuries, prior ipsilateral knee surgery, concomitant unicompartmental knee arthroplasty or high tibial osteotomy, ACL agenesis, and unknown date of tear. A total of 1,317 patients were included in the final analysis, with a median age of 29 years (interquartile range (IQR) 23 to 38). The median preoperative Tegner Activity Score (TAS) was 6 (IQR 6 to 7). Patients were categorized into four groups according to the delay to ACLr: < three months (427; 32%), three to six months (388; 29%), > six to 12 months (248; 19%), and > 12 months (254; 19%). Chondral injury was assessed during arthroscopy using the International Cartilage Regeneration and Joint Preservation Society classification, and its association with delay to ACLr was analyzed using multivariable analysis. Results: In the medial compartment, delaying ACLr for more than 12 months was associated with an increased rate (odds ratio (OR) 1.93 (95% confidence interval (CI) 1.27 to 2.95); p = 0.002) and severity (OR 1.23 (95% CI 1.08 to 1.40); p = 0.002) of chondral injuries, compared with < three months, with no association in patients aged > 50 years old. No association was found for shorter delays, but the overall dose-effect analysis was significant for the rate (p = 0.015) and severity (p = 0.026) of medial chondral injuries. Increased TAS was associated with a significantly reduced rate (OR 0.88 (95% CI 0.78 to 0.99); p = 0.036) and severity (OR 0.96 (95% CI 0.92 to 0.99); p = 0.017) of medial chondral injuries. In the lateral compartment, no association was found between delay and chondral injuries. Conclusion: Delay was associated with an increased rate and severity of medial chondral injuries in a dose-effect fashion, in particular for delays > 12 months. Younger patients seem to be at higher risk of chondral injury when delaying surgery. The timing of ACLr should be optimally reduced in this population.

Is Cemented Dual-Mobility Cup a Reliable Option in Primary and Revision Total Hip Arthroplasty: A Systematic Review.

Background: Instability is a common complication following total hip arthroplasty (THA). The dual mobility cup (DMC) allows a reduction in the dislocation rate. The goal of this systematic review was to clarify the different uses and outcomes according to the indications of the cemented DMC (C-DMC). Methods: A systematic review was performed using the keywords "Cemented Dual Mobility Cup" or "Cemented Tripolar Cup" without a publication year limit. Of the 465 studies identified, only 56 were eligible for the study. Results: The overall number of C-DMC was 3452 in 3426 patients. The mean follow-up was 45.9 months (range 12-98.4). In most of the cases (74.5%) C-DMC was used in a revision setting. In 57.5% DMC was cemented directly into the bone, in 39.6% into an acetabular reinforcement and in 3.2% into a pre-existing cup. The overall dislocation rate was 2.9%. The most frequent postoperative complications were periprosthetic infections (2%); aseptic loosening (1.1%) and mechanical failure (0.5%). The overall revision rate was 4.4%. The average survival rate of C-DMC at the last follow-up was 93.5%. Conclusions: C-DMC represents an effective treatment option to limit the risk of dislocations and complications for both primary and revision surgery. C-DMC has good clinical outcomes and a low complication rate.

Functional Alignment Philosophy in Total Knee Arthroplasty - Rationale and technique for the varus morphotype using a CT based robotic platform and individualized planning.

INTRODUCTION: Alignment techniques in total knee arthroplasty (TKA) continue to evolve. Functional alignment (FA) is a novel technique that utilizes robotic tools to deliver TKA with the aim of respecting individual anatomical variations. The purpose of this paper is to describe the rationale and technique of FA in the varus morphotype with the use of a robotic platform. RATIONALE: FA reproduces constitutional knee anatomy within quantifiable target ranges. The principles are founded on a comprehensive assessment and understanding of individual anatomical variations with the aim of delivering personalized TKA. The principles are functional pre-operative planning, reconstitution of native coronal alignment, restoration of dynamic sagittal alignment within 5° of neutral, maintenance of joint-line-obliquity and height, implant sizing to match anatomy and a joint that is balanced in flexion and extension through manipulation of implant positioning rather than soft tissue releases. TECHNIQUE: An individualized plan is created from pre-operative imaging. Next, a reproducible and quantifiable method of soft tissue laxity assessment is performed in extension and flexion that accounts for individual variation in soft tissue laxity. A dynamic virtual 3D model of the joint and implant position that can be manipulated in all three planes is modified to achieve target gap measurements while maintaining the joint line phenotype and a final limb position within a defined coronal and sagittal range. CONCLUSION: Functional alignment is a novel knee arthroplasty technique that aims to restore constitutional bony alignment and balance the laxity of the soft tissues by placing and sizing implants in a manner that it respects the variations in individual anatomy. This paper presents the approach for the varus morphotype.

Using standard-length compactors to implant short humeral stems in total shoulder arthroplasty: A cadaver study of humeral stem alignment.

BACKGROUND: Short-stem implants in shoulder arthroplasty were recently developed and reported clinical outcomes are good. However, radiological analysis often reveals humeral stem misalignment in the frontal plane, along with high filling ratios that can lead to proximal bone remodeling under stress shielding. The aim of this cadaveric study was to test whether using compactors for standard-length (> 100 mm) stems to implant short (< 100 mm) stems reduces the risk of stem misalignment without compromising in terms of a higher filling ratio. METHODS: In a cadaveric study, twenty short stems were implanted using instrumentation for standard-length stems. Alignment and filling ratios were evaluated on anteroposterior radiographs for both the compactors and the stems. The angular deviations (α) from the humeral axis of the compactors and the short stems were measured. Misalignment was defined as |α| > 5°. Metaphyseal and diaphyseal filling ratios were calculated and defined as either high (≥ 0.7) or low (< 0.7). RESULTS: The median angular deviations of the compactors and the short stems were respectively 1.6° (range, 0.03 to 5.9°) and 1.3° (range, 0.3 to 9.6°). Nineteen of the 20 compactors (95%) and 17/20 short stems (85%) were correctly aligned. The proportions of correctly aligned compactors and stems were not significantly different (95% CI, -0.33 to 0.11; Z-test of proportions p = .60), and the respective angular deviations were significantly correlated (Spearman ρ = .60, p = 0.006). The diaphyseal and metaphyseal filling ratios of the compactors and the stems were all low. CONCLUSIONS: In this series of 20 implants in cadavers, the narrow short humeral stems implanted with compactors for standard-length stems were correctly aligned with the humeral axis. This approach may be a way to achieve both correct frontal alignment and low filling ratios.

Similar outcomes including maximum knee flexion between mobile bearing condylar-stabilised and fixed bearing posterior-stabilised prosthesis: a case control study.

PURPOSE: Prosthesis design influences stability in total knee arthroplasty and may affect maximum knee flexion. Posterior-stabilised (PS) and condylar-stabilised (CS) designed prosthesis do not require a posterior-cruciate ligament to provide stability. The aim of the current study was to compare the range of motion (ROM) and clinical outcomes of patients undergoing cemented total knee arthroplasty (TKA) using either a PS or CS design prosthesis. METHODS: A total of 167 consecutive primary TKAs with a CS bearing (mobile deep-dish polyethylene) were retrospectively identified and compared to 332 primary TKA with a PS constraint, with similar design components from the same manufacturer. Passive ROM was assessed at last follow-up with use of a handheld goniometer. Clinical scores were assessed using Patient-Reported Outcome Measures (PROMs); International Knee Society (IKS) knee and function scores and satisfaction score. Radiographic assessment was performed pre and post operatively consisting of mechanical femorotibial angle (mFTA), femoral and tibial mechanical angles measured medially (FMA and TMA, respectively) on long leg radiographs, tibial slope and patella height as measured by the Blackburne-Peel index (BPI). RESULTS: Both groups had a mean follow-up of 3 years (range 2-3.7 years). Mean post-operative maximum knee flexion was 117° ± 4.9° in the PS group and 119° ± 5.2° in the CS group (p = 0.29). Postoperative IKS scores were significantly improved in both groups compared to preoperative scores (p < 0.01). The mean IKS score in the PS group was 170.9 ± 24.1 compared to 170.3 ± 22.5 in the CS group (p = 0.3). Both groups had similar radiographic outcomes as determined by coronal and sagittal alignment, tibial slope and posterior condylar offset ratio measurements. When considering the size of tibial slope change and posterior-condylar offset ratio, there was no differences between groups (p = 0.4 and 0.59 respectively). The PS group had more interventions for post-operative stiffness (arthrolysis or manipulation under anaesthesia) 8 (2.7%) compared to 1 (0.6%) in the CS group (p = 0.17). CONCLUSION: Condylar-stabilised TKA have similar patient outcomes and ROM at a mean follow-up of 3 years compared to PS TKA. Highly congruent inserts could be used without compromising results in TKA at short term. LEVEL OF EVIDENCE: Level IV, retrospective case control study.