Performance of medial pivot, posterior stabilized and rotating platform total knee arthroplasty based on anteroposterior stability and patient-reported outcome measures; a multicentre double-blinded randomized controlled trial of 210 knees.

BACKGROUND: Despite advancements in total knee arthroplasty (TKA), 10-20% of patients remain dissatisfied after surgery. Improved anteroposterior (AP) stability provided by medial pivot (MP) implants may theoretically lead to higher patient satisfaction. METHODS: AP stability and patient-reported outcome measures (PROMs) at one-year postsurgery were compared between patients who underwent TKA with MP- (n = 121), posterior stabilized (PS; n = 53) and rotating platform (RP; n = 57) implants in a double-blind multicentre randomized controlled trial (Dutch Trial Register: NL6856, 21-02-2018). AP stability was assessed at 30°, 60° and 90° of knee flexion using a KT-2000 arthrometer. PROMs were measured preoperative and one-year postsurgery. RESULTS: MP-TKA provided significant better AP stability at early flexion (30°) compared to PS- and RP-TKA (median [IQR]; 1.79 [1.14-2.77] mm vs. 3.31 [2.51-4.08] mm vs. 2.82 [1.80-4.03] mm, p < 0.001). Additionally, MP-TKA provided significant better AP stability at mid-flexion (60°) compared to PS-TKA (1.75 [1.23-2.36] mm vs. 2.14 [1.49-2.83] mm, p = 0.014). PROM improvements were comparable between implant designs. AP laxity of ≥ 4 mm at early flexion was independently of implant design associated with significantly worse Kujala scores. The incidence of ≥ 4 mm AP laxity at any knee angle was however not significantly different between implant designs. CONCLUSION: MP-, PS- and RP-TKA all provide excellent and comparable results. Although MP-TKA provided better AP stability at early flexion compared to PS- and RP-TKA, this was found to be unrelated to improved PROMs in favour of MP-TKA. More studies focusing on early and mid-flexion performance based differences between MP and other TKA designs are required to confirm our findings. Other non-implant related factors may play a more important role in the performance of TKA and are potentially worthwhile examining.

Ankle Instability: Facts and Myths to Protect Your Cartilage Repairing.

The majority of patients with an osteochondral lesion of the talus (OLT) report a history of trauma. Therefore, it is important to assess for concomitant ankle instability when dealing with patients with a symptomatic OLT. The History; Alignment; Ligaments; Others "(HALO)" approach can be a helpful tool in the evaluation of patients with an OLT. If conservative treatment fails, surgery may be indicated. Although there is a lack of comparative studies investigating the effect of stabilization procedures on cartilage repair, we believe that addressing instability is a key factor in improving patient outcome.

A Lateral Extra-articular Procedure Reduces the Failure Rate of Revision Anterior Cruciate Ligament Reconstruction Surgery Without Increasing Complications: A Systematic Review and Meta-analysis.

BACKGROUND: Lateral extra-articular procedures are becoming increasingly popular in association with anterior cruciate ligament (ACL) reconstruction, especially in patients with persistent rotatory instability and in a high-risk population. However, few studies have investigated the outcomes of the lateral extra-articular procedure as an associated procedure in an ACL revision (R-ACLR) setting and its benefit with respect to isolated intra-articular reconstruction. HYPOTHESIS: Lateral extra-articular procedures reduce the failure rate of revision ACL reconstruction (R-ACLR). PURPOSE: To compare subjective outcomes, knee stability, and failure and complication rates between patients who underwent ACL revision with and without an associated lateral extra-articular procedure. STUDY DESIGN: Systematic review and meta-analysis; Level of evidence, 3. METHODS: A systematic search of the PubMed, Cochrane, and OVID databases was performed on September 2022 in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Eligible studies were trials directly comparing patients who had isolated ACL revision with patients who had ACL revision associated with lateral extra-articular procedures at a minimum follow-up of 2 years. A meta-analysis was performed, and bias and the quality of the evidence were rated according to the Newcastle-Ottawa Scale. The meta-analysis was conducted according to the PRISMA guidelines. RESULTS: Eight studies were included: a total of 334 patients were treated with isolated revision (isolated (R-ACLR)) and 342 treated with combined revision and a lateral extra-articular procedure (combined (R-ACLR)). For the failure rate, the meta-analysis showed a significantly decreased relative risk reduction of 54% (P = .004) in patients with combined (R-ACLR) with respect to isolated R-ACL, whereas no difference in complication rate was observed. The combined (R-ACLR) group demonstrated a decreased risk ratio of 50% (P = .002) for having a positive pivot-shift test result and a relative risk reduction of 68% (P = .003) for having a grade 2-3 pivot shift when compared with the isolated (R-ACLR) group. Finally, no significant differences were observed among the lateral extra-articular procedures. CONCLUSION: The addition of a lateral extra-articular procedure to revision ACL significantly reduced the failure rate and postoperative pivot shift without increasing the complication rate. Anterolateral ligament reconstruction and a lateral extra-articular procedure with iliotibial band were effective in improving the outcomes of revision ACL reconstruction. Further high-level studies could help to clarify which subgroup of patients could particularly benefit from an anterolateral procedure in the context of ACL revision.

Does an early post traumatic knee brace reduce the incidence of knee rotational instability?

PURPOSE: Several anterolateral stabilization procedures have been developed recently to address rotational instability of the knee. Currently, these procedures tend to be systematically used by some practitioners. However, antero-lateral structures of the knee (including the anterolateral ligament, ALL) have a self-healing potential which can reduce the need to perform an antero-lateral procedure. In this study, it was hypothesized that early post-traumatic immobilization of the knee with a knee brace would allow partial healing of antero-lateral structures and also allow control of the pivot shift, thus avoiding antero-lateral extra-articular stabilization. The objective of this study was to compare the severity of pivot shift between two groups of patients who all experienced anterior cruciate ligament (ACL) tear and respectively underwent post-traumatic immobilization of the knee versus no immobilization. METHODS: This was a comparative, multicentric (three centers' study) retrospective, consecutive study including 168 patients who underwent ACL reconstruction between May and September 2022. The application or not of post-traumatic immobilization and its duration, the severity of pivot shift observed in the operating room under general anesthesia, the presence of anterolateral lesions as revealed by MRI and the patients' pre-injury sport activity were recorded. RESULTS: A grade 3 pivot shift was found in 44 patients (27%). It was more frequently observed in the group without a brace compared to the group with a knee brace (18 patients out of 36: 50% versus 26 patients out of 132: 19.7%; p = 0.0012). Wearing a brace, whether hinged (OR = 0.221, [0.070-0.652]; p = 0.006) or not (OR = 0.232, [0.076-0.667]; p = 0.0064), was protective from the risk of developing a significant pivot shift. CONCLUSION: This study demonstrated that the presence of pivot-shift was lower in the patients that had an early post-injury knee brace before their ACL reconstruction. Based on this result, systematic brace placement could be advocated for in patients after knee trauma. LEVEL OF EVIDENCE: III, prognostic retrospective case-control study.

Stability of novel cow-hitch suture button coracoid bone graft fixation in Latarjet procedures: a biomechanical study.

BACKGROUND: The Latarjet procedure is widely used to address anterior shoulder instability, especially in case of glenoid bone loss. Recently, cortical suture button fixation for coracoid transfer has been used to mitigate complications seen with screw placement. The aim of this biomechanical study was to evaluate the stability of a novel and cost-effective cow-hitch suture button technique, designed to be performed through a standard open deltopectoral approach, and compare this to a well-established double suture button technique. MATERIALS AND METHODS: We randomly assigned 12 fresh frozen cadaveric shoulders to undergo the Latarjet procedure with either 4 suture button (S&N EndoButton) fixations (SB group; n = 6, age 72 ± 9.8 years) or cow-hitch suture button technique using a 1.7-mm FiberTape looped sequentially in 2 suture buttons (Arthrex Pectoralis Button) placed from anterior on the posterior glenoid (CH-SB group; n = 6, age 73 ± 9.3 years). After fixation, all shoulders underwent biomechanical testing with direct loading on the graft via a material testing system. Cyclic loading was performed for 100 cycles (10-100 N) to determine axial displacement with time; each graft was then monotonically loaded to failure. RESULTS: The maximum cyclic displacement was 4.3 ± 1.6 mm for the cow-hitch suture button technique and 5.0 ± 1.7 mm for the standard double suture button technique (P = .46). Ultimate load to failure and stiffness were, respectively, 190 ± 82 N and 221 ± 124 N/mm for the CH-SB technique and 172 ± 48 N and 173 ± 34 N/mm for the standard double SB technique (P = .66 and .43). The most common failure mode was suture cut-through at the anteroinferior aspect of the glenoid for both fixation groups. CONCLUSIONS: The cow-hitch suture button technique resulted in a similar elongation, stiffness, and failure load compared to an established double suture button technique. Therefore, this cost-effective fixation may be an alternative, eligible for open approaches, to the established double suture button techniques.

Effects of textured insoles and elastic braces on dynamic stability in patients with functional ankle instability.

BACKGROUND: Functional ankle instability (FAI) is a common condition that affects individuals who have experienced previous ankle sprains. Textured insoles and elastic ankle braces have been previously used as interventions to improve stability in FAI patients. However, the optimal combination of these interventions has not been fully explored. The objective of this study was to investigate the effects of different types of textured insoles and elastic ankle braces on the dynamic stability of individuals diagnosed with FAI. METHODS: The study involved 18 FAI patients who performed single-leg landing tasks with and without wearing an eight-band elastic ankle brace while wearing textured insoles with protrusion heights of 0 mm, 1 mm, and 2 mm. The dynamic posture stability index (DPSI) and its components in the anterior-posterior (APSI), mediolateral (MLSI) and vertical (VSI) directions were calculated from the ground reaction force collected from the Kistler force plate during the first three seconds of the landing tasks. RESULTS: A significant interaction was found between textured insole type and ankle brace for DPSI (P = 0.026), APSI (P = 0.001), and VSI (P = 0.021). However, no significant interaction was observed for MLSI (P = 0.555). With elastic ankle braces, textured insoles with 1-mm protrusions significantly enhanced anterior-posterior, mediolateral, vertical, and overall stability compared to textured insoles with no and 2 mm protrusions (P < 0.05). Without elastic ankle braces, textured insoles with 1-mm protrusions significantly improved the anterior-posterior (P = 0.012) and overall stability (P = 0.014) of FAI patients compared to smooth insoles. CONCLUSIONS: The combination of textured insoles with 1-mm protrusion heights and an elastic ankle brace could enhance the dynamic stability of individuals with FAI, potentially mitigating the risk of ankle sprains.

Physiologic Motion in the Intact and Unstable Syndesmosis During Plantigrade Weightbearing in Controlled Ankle Motion Boots.

Consensus has not been reached for the optimal postoperative care after high ankle sprain and syndesmotic fixation. A potential drawback of earlier return to activity is greater instability of the ankle and fixation failure. The controlled ankle motion (CAM) boot has been an effective implementation to stabilize the leg and may aid in safe early weightbearing status. However, there is insufficient study of its effect on motion in the syndesmosis following injury. Hence, the aim of this cadaveric study was to determine the stability of the ankle with a CAM boot at 3 levels of injury: syndesmosis ligaments intact (no injury), syndesmosis ligaments cut, and syndesmosis and fibula cut. Six cadaveric legs were subjected to each level of injury and axially loaded at 1 Hz between 100 N-1.5 times body weight for 50 seconds, and axial force, axial displacement, and optical tracking data were recorded. It was found that the ankle, when protected by the CAM boot, maintained syndesmosis motion with no difference (p > .05) from the uninjured state, regardless of syndesmotic ligament and fibular injury. This finding was consistent across anterior-posterior, medial-lateral, and superior-inferior axes. Overall, our study may suggest that early weightbearing with a CAM boot maintains a physiologically range of motion in the syndesmosis.

Posterolateral stabilization of the elbow by autologous ligament reconstruction to limit long-term development of osteoarthritis.

BACKGROUND: Posterolateral instability is the most frequent form of both acute and chronic elbow instability. Joint incongruity due to posterolateral unlocking leads to shear and compression stress of the internal aspect of the humeroulnar joint. We carried out long-term analysis of patients with posterolateral elbow instability in order to determine whether, in addition to improving their symptoms, reconstruction of the lateral collateral ligament complex may play a protective role against the development of post-traumatic osteoarthritis. We hypothesized that ligament reconstruction according to the technique of O'Driscoll stabilizes the elbow and also limits the development of osteoarthritis in the long term. METHODS: Patients with symptomatic posterolateral instability of the elbow and who underwent ligament reconstruction according to the technique of O'Driscoll from January 1995 to December 2010 were identified and retrospectively included for 2 follow-up evaluations at a mean of 5 and 14 years. RESULTS: Fourteen elbows in 14 patients were included. All had a negative lateral pivot shift test and none reported a new episode of instability. Two patients (14%) had osteoarthritis. The 2 radiographic evaluations showed no progression of osteoarthritis. Osteoarthritis developed in 33% of patients with intra-articular fracture. In simple dislocations, pre-existing osteoarthritic lesions were stabilized and there were no new cases of osteoarthritis. CONCLUSION: Elbow ligament reconstruction according to the technique of O'Driscoll gives effective posterolateral stabilization and appears to protect against progression to osteoarthritic degeneration in the long term. In the absence of associated lesions, it prevents the development of osteoarthritis or the worsening of pre-existing osteoarthritis.

Functional Interaction of the Cruciate Ligaments, Posteromedial and Posterolateral Capsule, Oblique Popliteal Ligament, and Other Structures in Preventing Abnormal Knee Hyperextension.

BACKGROUND: The ligaments and soft tissue capsular structures of the knee joint that provide a resisting force to prevent abnormal knee hyperextension have not been determined. This knowledge is required for the diagnosis and treatment of knee hyperextension abnormalities. PURPOSE: To determine the resisting moment of knee ligament and capsular structures that resist knee hyperextension. HYPOTHESIS: The combined posteromedial and posterolateral capsular structures function to provide a major restraint to prevent abnormal knee hyperextension. The anterior and posterior cruciate ligaments resist knee hyperextension but function as secondary restraints. STUDY DESIGN: Descriptive laboratory study. METHODS: A 6 degrees of freedom robotic system determined intact laxity limits in 24 cadaveric knees from 0° to 100° of knee flexion for anteroposterior limits at ±135 N, abduction-adduction limits at ±7 N·m, and external-internal limits at ±5 N·m. One loading method (n = 14 knees) used a static loading sequence with knee hyperextension to 27-N·m torque while maintaining all other degrees of freedom at zero load during sequential soft tissue cutting. The second method (n = 10 knees) used a cyclic loading sequence to decrease viscoelastic effects with soft tissue cutting at 0° of extension, followed by knee hyperextension to 27-N·m torque and cycled back to 0°. Selective soft tissue cuttings were performed of the following: oblique popliteal ligament, fabellofibular ligament, posterolateral capsule, posteromedial capsule with posterior oblique ligament, cruciate ligaments, lateral collateral ligament, popliteus, anterolateral ligament and iliotibial band, and superficial plus deep medial collateral ligaments. The sequential loss in the restraining moment with sectioning provides the function of that structure in resisting knee hyperextension. RESULTS: The median resisting force to knee hyperextension, in descending order, was the posteromedial capsule and posterior oblique ligament (21.7%), posterorolateral ligament and fabellofibular ligament (17.1%), anterior and posterior cruciate ligaments (13% and 12.9%, respectively), superior and deep medial collateral ligament (9.6%), oblique popliteal ligament (7.7%), and lateral collateral ligament (5.4%). The combined posterior capsular structures provided 54.7% and the anterior and posterior cruciate ligaments 25.3% of the total resisting moment to prevent knee hyperextension. CONCLUSION: Diagnosis of abnormal knee hyperextension involves a combination of multiple ligament and soft tissue structures without 1 primary restraint. The posteromedial and posterolateral capsular structures provided the major resisting moment to prevent knee hyperextension. The cruciate ligaments produced a lesser resisting moment to knee hyperextension. CLINICAL RELEVANCE: This is the first study to comprehensively measure all of the knee ligaments and capsular structures providing a resisting moment to abnormal knee hyperextension. These data are required for diagnostic and treatment strategies on the pathomechanics of abnormal knee hyperextension in patients after injury or developmental cases.

Remplissage reduces recurrent instability in high-risk patients with on-track Hill-Sachs lesions.

BACKGROUND: The purpose of this study was to compare recurrent instability rates between patients with on-track Hill-Sachs lesions who underwent arthroscopic labral repair (ALR) alone and those who underwent ALR with remplissage (ALR-R). Our hypothesis was that ALR-R would decrease the rate of recurrent instability, especially among patients at high risk of recurrent instability after ALR, such as contact athletes with near-track Hill-Sachs lesions. METHODS: We performed a multicenter, retrospective analysis of patients aged 14-50 years with on-track Hill-Sachs lesions who underwent ALR-R or ALR without remplissage between January 2014 and December 2019 with minimum 2-year follow-up. The exclusion criteria included prior ipsilateral shoulder surgery, >15% glenoid bone loss (GBL), off-track Hill-Sachs lesion, concomitant shoulder procedure, and connective tissue disorder. Age, sex, follow-up, and contact sports participation were recorded. GBL, Hills-Sachs interval (HSI), glenoid track, and distance to dislocation (DTD) were determined from preoperative magnetic resonance imaging scans. Affected-shoulder range of motion, Western Ontario Shoulder Instability Index scores, Subjective Shoulder Value scores, and recurrent dislocation and/or revision surgery status were also collected. A subgroup analysis was performed on "high-risk" patients (defined as participants in contact sports with DTD <10 mm) from each cohort. RESULTS: The ALR-R cohort included 56 patients, and the ALR cohort included 127. ALR-R patients had greater GBL (P = .004) and a greater HSI (P < .001). In the ALR-R cohort, only 1 patient (1.8%) had a recurrent dislocation and there were no revision operations. In comparison, in the ALR cohort, 14 patients (11.0%) had recurrent dislocations (P = .040) and 8 (6.3%) underwent revision operations (P = .11). Univariate analysis showed that remplissage protected against recurrent dislocation (P = .040) whereas younger age (P = .004), contact sports participation (P = .001), and increased GBL (P = .048) were associated with recurrent dislocation. Multivariate analysis showed that HSI (P = .001) and contact sports participation (P = .002) predicted recurrent dislocation. Among high-risk patients, only 1 patient (4.2%) in the ALR-R group had a recurrent instability event vs. 6 (66.7%) in the ALR group (P < .001). The high-risk ALR-R subgroup also had significantly better final Western Ontario Shoulder Instability Index (P = .008) and Subjective Shoulder Value (P = .001) scores than the high-risk ALR subgroup. CONCLUSIONS: Anterior shoulder instability patients with on-track Hill-Sachs lesions have lower recurrent dislocation rates after ALR plus remplissage when compared with ALR alone. This is especially true for high-risk patients, such as contact athletes with a DTD <10 mm.

Accuracy of femoral tunnel positioning in medial patellofemoral ligament reconstruction: anatomic insertion leads to better clinical outcome.

PURPOSE: The medial patello-femoral ligament (MPFL) is considered the primary restraint against patellar dislocation and its reconstruction is indicated in recurrent patellar instability. An anatomical positioning of MPFL femoral insertion is recommended to achieve satisfactory clinical outcomes and prevent osteoarthritis (OA) due to an altered kinematics. The purpose of the study was first to assess the relationship between correct femoral tunnel position and better clinical outcomes and lower patellofemoral osteoarthritis rate. Second, correlation of outcomes with factors potentially affecting the results, such as the type of graft, patellar height and trochlear dysplasia. METHODS: Fifty-three patients (58 knees) who underwent MPFL reconstruction between 2009 and 2018 by a senior knee surgeon were retrospectively evaluated. Knee radiographs were performed before surgery, 12 months later and at last follow-up to assess trochlear dysplasia, patellar height and patellofemoral OA. The tibial tuberosity-trochlear groove (TT-TG) value was measured on a CT scan. The accuracy of graft positioning was evaluated on sagittal radiographs according to Schöttle et al. Subjective outcomes were collected before surgery, at 12 months and at last follow-up using several validated scores. RESULTS: Forty-six patients (51 knees) with a mean age of 24.1 ± 7.4 years were included in the study. Mean follow-up was 8.9 ± 2.1 years. A significant improvement in all clinical scores was observed at 12 months and final follow-up. Anatomic Insertion (AI) of reconstructed MPFL was considered optimal in 33 (64.7%) and sub-optimal in 18 (35.3%) patients. Sub-optimal AI resulted in lower Kujala, IKCD and higher VAS score (p < 0.01); moreover, for every 1 mm distance in any direction from the ideal insertion, a decrease of 0.8 [95% CI (-1.4; -0.2)] in Kujala score and 0.8 [95% CI (-1.3; -0.3)] in IKDC was observed. At final follow-up, 8 patients presented patellofemoral OA Iwano grade 3 (15.7%): although that incidence did not correlate to graft positioning, the use the artificial ligament in all these cases appeared to be significant. CONCLUSION: The present study confirms the importance of an optimal anatomic femoral insertion in MPFL reconstruction, reporting a significant positive correlation between graft positioning and clinical outcome. No significant correlations were found between anatomic insertion and patello-femoral OA development. LEVEL OF EVIDENCE: IV.

Lateral Collateral Ligament and Biceps Femoris Tendon Fixation with a Suture Anchor to the Tibial Metaphysis after Proximal Fibula En Bloc Resections Preserve Lateral Knee Stability.

This study aims to analyze the functional outcomes and lateral knee stability of patients who underwent lateral collateral ligament (LCL) and biceps femoris tendon reconstruction with suture anchors after proximal fibula en bloc resection for bone tumors. Patients who underwent proximal fibular en bloc resection between 2007 and 2018 were retrospectively viewed. Patients were invited to visit the clinic, and their functional scores were evaluated using the Musculoskeletal Tumor Society Scoring (MSTS) system. Lateral knee stability was evaluated by varus stress radiographs obtained at 20 degrees of flexion, and the range of motion (ROM) of the bilateral knee was assessed. Side-to-side differences were graded according to the International Knee Documentation Committee (IKDC) criteria and compared between types I and II resections. A total of 17 patients (4 males and 13 females) with a mean age of 31.1 ± 17.1 (range: 13-65) years at the time of surgery were available for radiological and clinical examination at a mean follow-up of 68.6 ± 36.4 (range: 22-124) months after surgery. In terms of ROM measurements, IKDC grades and side-to-side differences in both flexion and extension were not significantly different between the groups. On varus stress radiographs, lateral knee gapping was measured to be 0.93 ± 0.91 mm in type-I resections and 1.83 ± 0.45 mm in type-II resections, and statistically significant differences were detected among the groups (p = 0.039). When the values were graded according to IKDC criteria, none of the knees were classified as abnormal, and no difference was observed between the groups. Mean MSTS score of patients with type-I resections was significantly higher than those of patients with type-II resections (92.7 vs. 84.4%, p = 0.021). In the subscale analysis, a significant difference was observed in the support scores (type I = 94.5%, type II = 70%; p = 0.001). The reattachment of LCL and biceps femoris tendon to the tibial metaphysis with a suture anchor is a simple and effective method to prevent lateral knee instability after proximal fibula resections.

Arthroscopic centralization reduces extrusion of the medial meniscus with posterior root defect in the ACL reconstructed knee.

PURPOSE: The purpose of this study was to evaluate the effects of arthroscopic meniscal centralization reinforcement for a medial meniscus (MM) posterior root defect on knee kinematics and meniscal extrusion in the anterior cruciate ligament reconstructed (ACLR) knee. The hypothesis was that the medial meniscus centralization would reduce extrusion and anterior laxity in ACLR knee with a medical meniscal defect. METHODS: Fourteen fresh-frozen human cadaveric knees were tested using a six-degrees-of-freedom robotic system under the following loading conditions: (a) an 89.0 N anterior tibial load, (b) 5.0 Nm internal and external rotational torques, (c) a 10.0 Nm valgus and varus loadings, and (d) a combined 7.0 Nm valgus moment and then a 5.0 Nm internal rotation torque as a static simulated pivot shift. The tested knee states included: (1) anatomic single-bundle cruciate ligament reconstruction with intact medial meniscus (MM Intact), (2) anatomic single-bundle cruciate ligament reconstruction with medial meniscus posterior root defect (MM Defect), (3) Anatomic single-bundle cruciate ligament reconstruction with medial meniscus arthroscopic centralization (MM Centralization). Medial meniscus arthroscopic centralization was performed using 1.4 mm anchors with #2 suture. The MM extrusion (MME) was measured using ultrasound under unloaded and varus loading conditions at 0° and 30° of flexion. RESULTS: Anterior tibial translation (ATT) increased significantly with MM posterior root defect compared to MM intact at all flexion angles. With MM centralization, ATT was not significantly different from the intact meniscus at 15° and 30° of flexion. Meniscus extrusion increased significantly with the root defect compared to intact meniscus and decreased significantly with meniscal centralization compared to the root defect at both flexion angles. CONCLUSIONS: In ACL reconstruction, cases involving irreparable medial meniscal posterior root tears, applying arthroscopic centralization for avoiding the meniscal extrusion should be considered. Clinically, in ACL reconstruction cases with irreparable medial meniscal posterior root tears, applying arthroscopic meniscal centralization for avoiding the meniscal extrusion should be considered. Meniscal centralization decreases the extrusion of the MM and offers improvements in knee laxity.

Evaluation of Dural Parameters at C1 Level in Patients with Chiari 1 Malformation Following Foramen Magnum and C1 Posterior Arch Removal: Introduction of a Novel Concept to Decompress without Affecting Stability.

Background: Chiari 1 malformation has crowding at craniovertebral junction (CVJ), treated by Foramen magnum decompression (FMD) but is associated with high failure rates, which is explained by recently introduced concept of central instability. So, we propose a new concept of relieving this crowding without affecting stability. Objective: To derive a threshold for coring out of internal surface of C1 posterior arch instead of complete laminectomy accompanying FMD. Methods and Material: We prospectively included nine patients with a mean age of 25.33 ± 7.97 years, diagnosed with ACM-1 without AAD, who were operated with FMD and lax duraplasty and C1 laminectomy. The preoperative dural diameter and area covered under the dura at the level of C1 were measured and compared with the postoperative state. Results were analyzed to derive a cut-off threshold which could be drilled from the inner aspect of C1 arch. Results: The postoperative AP diameter of the dura increased statistically significantly from pre-op; however, the AP extension was less than the preoperative diameter with posterior arch included. Likewise, the area spanned by the dura increased statistically significantly from pre-op but was less than the cumulative area of dura with C1 arch included in pre-op. Analyzing all, a mean cut-off of 50.58% was achieved. Conclusion: The authors suggest FMD with partial coring (~50%) of the inner part of arch of C1, instead of full-thickness laminectomy with a wider length of coring as the target, and this will serve the purpose intended, without increasing mobility.

Editorial Commentary: Two Fixation Points Are Better for Medial Patellofemoral Ligament Reconstruction-To Minimize Complications, Bone Tunnels Should Be Avoided.

Medial patellofemoral ligament (MPFL) reconstruction has gained in popularity over the past 15 years, with most studies showing a clear advantage over techniques such as MPFL repair or medial imbrication for the treatment of patellar instability. A debate continues as to the type of fixation on the patella, tunnel versus suture anchor, as well as the number of fixation points. In fact, some senior patellofemoral surgeons have opted away from patellar bony fixation altogether to avoid complications associated with patellar fixation such as fracture or penetration of the articular cartilage. In my practice, I prefer to use 2 all-suture suture anchors for patellar fixation as there is minimal risk of fracture or significant cartilage damage compared with tunnel drilling or placement of larger suture anchors. The graft choice for MPFL reconstruction has been shown to be relatively unimportant, and for this reason, I typically choose gracilis allograft to avoid graft-site morbidity and hamstring weakness.

Does an Internal Joint Stabilizer and Standardized Protocol Prevent Recurrent Instability in Complex Persistent Elbow Instability?

BACKGROUND: The treatment of complex persistent elbow instability after trauma is challenging. Previous studies on treatments have reported varied surgical techniques, which makes it difficult to establish a therapeutic algorithm. Furthermore, the surgical procedures may not sufficiently restore elbow stability, even with an additional device, and a noted high rate of arthritis progression.While a recently developed internal joint stabilizer effectively treats elbow instability, its clinical application for complex persistent elbow instability is limited and the standardized protocol is not well described. Additionally, we want to know whether the arthritis progression will cause a negative impact on the functional outcomes of complex persistent elbow instability. QUESTIONS/PURPOSES: (1) Does treatment of complex persistent elbow instability with a hinged internal joint stabilizer and a standardized protocol prevent recurrent instability and other complications? (2) What are the pre- to postoperative improvements in pain, disability, elbow performance, and ROM? (3) Is the development of post-traumatic arthritis associated with worse pain, disability, elbow performance, and ROM? METHODS: Between September 2014 and October 2019, we treated 22 patients for persistent dislocation or subluxation after initial treatment of traumatic elbow fracture-dislocations. Of those, we considered patients who were at least 20 years of age, with an interval of 6 weeks or more between the injury (initial treatment) and the index reconstructive procedure, which had been performed at our institute, as potentially eligible. During that time, we used an internal joint stabilizer with a standardized protocol for posttraumatic complex persistent elbow instability. We performed total elbow replacements in patients older than 50 years who had advanced elbow arthritis. Based on that, 82% (18 of 22) of patients were eligible; 14% (3 of 22) were excluded because total elbow replacements was undertaken, and another 5% (1 of 22) were lost before the minimum study follow-up of 1 year (median 24 months [range 12 to 63]), leaving 64% (14 of 22) for analysis in this retrospective study. We treated 14 patients (14 elbows) with posttraumatic complex persistent elbow instability with an internal joint stabilizer and a standardized protocol that comprised debridement arthroplasty with ulnar neurolysis, restoration of bony and ligamentous (reattachment) structures, application of an internal joint stabilizer, and early rehabilitation. There were eight men and six women in this study, with a median (range) age of 44 years (21 to 68). The initial elbow fracture-dislocation injury pattern was a terrible triad injury in seven patients, a posterolateral rotatory injury in four patients, and a posterior Monteggia fracture in three patients. Preoperative and follow-up radiographs were reviewed for evidence of recurrent instability and arthritis. Complications such as wound infection, seroma, neurovascular injury, and hardware complications were ascertained through chart review. Preoperative and postoperative VAS score for pain, DASH, and Mayo Elbow Performance Scores (MEPS) were collected and compared. Furthermore, extension-flexion and supination-pronation arcs were collected by chart review. We divided the patients into two groups according to whether or not they developed posttraumatic arthritis. We then presented the differences between pain, disability, elbow performance, and ROM. The hinged internal joint stabilizer was removed using another open procedure under general anesthesia 6 to 8 weeks after surgery. RESULTS: There were no recurrent instability during and after device removal. Seven patients developed complications, including wound infection, seroma, neurovascular injury, hardware complications, and heterotopic ossification. Two patients had complications related to internal joint stabilizers and three had complications linked to radial head prostheses. Median (range) preoperative to postoperative changes included decreased pain (VAS 5 [2 to 9] to 0 [0 to 3], difference of medians -5; p < 0.001), decreased disability (DASH 41 [16 to 66] to 7 [0 to 46], difference of medians -34; p < 0.001), improved function (MEPS 60 [25 to 70] to 95 [65 to 100], difference of medians 35; p < 0.001), improved extension-flexion arc (40° [10° to 70°] to 113° [75° to 140°], difference of medians 73°; p < 0.001), and supination-pronation arc (78° [30° to 165°] to 148° [70° to 175°], difference of medians 70°; p < 0.001). Between patients with and without development of post-traumatic arthritis, there were no differences in postoperative pain (VAS 0 [0 to 3] to 0 [0 to 1], difference of medians 0; p = 0.17), disability (DASH 7 [0 to 46] to 7 [0 to 18], difference of medians 0; p = 0.40), function (MEPS 80 [65 to 100] to 95 [75 to 100], difference of medians 15; p = 0.79), extension-flexion arc (105° [75° to 140°] to 115° [80° to 125°], difference of medians 10°; p = 0.40), and supination-pronation arc (155° [125° to 175°] to 135° [70° to 160°], difference of medians -20°; p < 0.18). CONCLUSION: In this small, retrospective study, we found that an internal joint stabilizer with a standardized treatment protocol could maintain concentric reduction while allowing early functional motion, and that it could improve clinical outcomes for patients with complex persistent elbow instability. However, patients must be counseled that the complications related to the radial head prostheses may occur, and that the benefits of early motion must compensate for an additional removal procedure and the risk of seroma formation. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Medial patellofemoral ligament reconstruction is superior to active rehabilitation in protecting against further patella dislocations.

PURPOSE: Isolated reconstruction of the medial patellofemoral ligament (MPFL-R) has become the predominant stabilizing procedure in the treatment of recurrent lateral patellar dislocation (LPD). To minimize the risk of re-dislocations, isolated MPFL-R is recommended in patients with no significant trochlea dysplasia and tibial tuberosity trochlear groove distance < 20 mm on computed tomography (CT). Incidentally, these criteria are the same that are used to identify first time LPD patients where conservative treatment is recommended. The purpose of this study was therefore to compare MPFL-R with active rehabilitation for patients with recurrent LPD (RLPD) in absence of the above mentioned underlying anatomical high-risk factors for further patellar dislocations. METHODS: RLPD-patients aged 12-30 without underlying anatomical high-risk factors for further LPD were randomized into treatment either with isolated MPFL-R or active rehabilitation provided and instructed by a physiotherapist. All patients underwent diagnostic arthroscopy for concomitant problems. The main outcome measure was persistent patellar instability at 12 months. Knee function at baseline and 12 months was asses using the following patient reported outcomes measures (PROMS); KOOS, Kujala, Cincinnati knee rating, Lysholm score and Noyes sports activity rating scale. RESULTS: Between 2010 and 2019, 61 patients were included in the study (MPFL-R, N = 30, Controls, N = 31). Persistent patellar instability at 12 months was reported by 13 (41.9%) controls, versus 2 (6.7%) in the MPFL-group (RR 6.3 (95% CI 1.5-25.5). No statistically significant differences in activity level were found between the MPFL-group and the Controls at neither baseline nor follow up. The patients with persistent instability at 12 months did not score significantly lower on any of the PROMs compared to their stable peers, regardless of study group. CONCLUSION: Patients with recurrent patellar dislocations have a six-fold increased risk of persistent patellar instability if treated with active rehabilitation alone, compared to MPFL-R in combination with active rehabilitation, even in the absence of significant anatomical risk factors. Active rehabilitation of the knee without MPFL-R improves patient reported knee function after one year, but does not protect against persistent patellar instability.

A Mid-Level Constrained Insert Reduces Coupled Axial Rotation but Not Coronal Mid-Flexion Laxity Induced by Joint Line Elevation in Posterior-Stabilized Total Knee Arthroplasty: A Computational Study.

BACKGROUND: Surgeons may resect additional distal femur during primary posterior-stabilized (PS) total knee arthroplasty (TKA) to correct a flexion contracture. However, the resultant joint line elevation (JLE) increases mid-flexion laxity. We determined whether a mid-level constraint (MLC) insert reduced mid-flexion laxity after JLE. METHODS: Six computational knee models were developed using computed tomography scans and average soft tissue properties yielding balanced extension gaps but with a 10° flexion contracture. Distal femoral resections of +2 and +4 mm were simulated with PS and MLC inserts. Varus-valgus ±10 Nm moments were applied at 30°, 45°, and 60° of flexion. Coronal laxity (the sum of varus-valgus angulation) and coupled axial rotation (the sum of internal/external rotation) were measured and compared between insert models. RESULTS: At 30° of flexion, coronal laxities with the PS insert at the +2 and +4 mm resections averaged 7.9° ± 0.6° and 11.3° ± 0.6°, respectively, and decreased by 0.8° (P = .06) and 1.0° (P = .07), respectively, with the MLC insert. PS rotational laxities at the +2 and +4 mm resections averaged 11.1° ± 3.9° and 12.5° ± 4.6°, respectively, and decreased by 5.6° (P = .01) and 7.1° (P = .02), respectively, with the MLC insert. Similar patterns were observed at 45° and 60° of flexion. CONCLUSION: With additional distal femoral resections to alleviate a flexion contracture, utilizing an MLC insert substantially reduced coupled axial rotation but had a minimal impact on coronal laxity compared to a PS insert. Efforts should be taken to avoid JLE in primary total knee arthroplasty as even MLC inserts may not mitigate coronal laxity.

Does the immediate repair of Bankart lesion following first dislocation reduce the chances of recurrence after arthroscopic repair in soldiers?

PURPOSE: The study attempted to compare the effects of immediate and delayed arthroscopic Bankart repair on the shoulder dislocation recurrence. METHODS: In total, 465 soldiers with first-time anterior shoulder dislocation were included in the study. Of the total, 285 soldiers underwent a quick arthroscopic Bankart repair procedure, whether 180 soldiers underwent a delayed repair procedure. The initial dislocation was traumatic in both groups and operated using the standard arthroscopic suture anchor repair technique. Patient's age, repair time since the first dislocation, number of dislocations before surgery, number of suture anchors used during the repair, duration of surgical procedure, duration from surgery to return to work, and recurrence of dislocation after surgery were recorded. Rowe score, Constant score, and American Shoulder and Elbow Surgeons score were used for clinical assessment. RESULTS: The operating time and recurrence rate were higher in the group subjected to delayed repair procedure than in the group subjected to immediate repair procedure. Repair timing was found to be crucial for a successful outcome. CONCLUSIONS: The findings suggest that Bankart repair must be performed immediately to minimize recurrence and other degenerative changes, which may require an additional surgical procedure for satisfactory repair. More studies are required to reach a definitive conclusion. LEVELS OF EVIDENCE: Level III.

Lateral-extra articular tenodesis vs. anterolateral ligament reconstruction in skeletally immature patients undergoing anterior cruciate ligament reconstruction.

PURPOSE OF REVIEW: The aim of this study was to review the most recent available evidence about lateral-extra articular tenodesis (LET) and anterolateral ligament (ALL) reconstruction in young patients treated for anterior cruciate ligament (ACL) injury. RECENT FINDINGS: The ALL of the knee acts as a secondary stabilizer of the knee preventing anterior translation and internal rotation. In vitro and in vivo biomechanical studies as well as prospective clinical trials have shown the importance of the ALL in knee biomechanics. The ALL injury has a synergetic impact on the knee stability in patients with acute ACL injury. ALL augmentation of ACL provides reduction of knee instability and graft failure and higher return to sport rates in high-risk patients. It has not been demonstrated that extra-articular procedures increase the risk of knee osteoarthritis secondary to knee over-constriction. Both Iliotibial band (ITB) ALL reconstruction and modified Lemaire LET have been shown safe and effective. Minimal biomechanical or clinical differences have been found between the two reconstruction methods. SUMMARY: Young patients with ACL tears and risk factors such as laxity or pivot shift willing to return to sports may benefit from ALL augmentation. Therefore, it is essential to identify these high-risk patients to individualize treatment.