Bone patellar tendon bone (B-PT-B) autograft ACLR reliably restores knee stability but has been associated with greater anterior knee pain. Data from patients enrolled in an ongoing clinical trial receiving B-PT-B autografts with post-operative MRI and PRO were evaluated. Excess bone following graft preparation were returned to the defects. Patellar bone defect length, width, and depth calculated as a percentage of the patient's patella were measured using MRI obtained 6 weeks and 1 year after ACLR. Longer relative patellar defects at 6 weeks were observed in patients who did not reach Patient Acceptable Symptom States in KOOS pain and KOOS Sports/Rec at 1 year. Larger relative patellar defect size at 6 weeks showed trends toward association with worse PROs at 1 year. Greater relative patellar defect size at 1 year correlated to worse PRO and related to failure to achieve PASS. These data suggest a positive effect of healing on mitigating symptoms related to patellar bone defects. The 1-year data further suggest that consideration be given to harvesting smaller bone plugs in patients with smaller patellae.

This lecture shows hamstring ACL reconstructions have a high failure rate particularly in young females. Adding a lateral procedure will lower the failure rate to similar to a BPB graft but a BPB + LET has a much lower failure rate . A hamstring ACL graft has a higher medial meniscal repair failure rate and a higher overall reoperation rate than BPB grafts

I will present the results of my survey of ACL Study Group members on the management of Partial ACL injuries, as diagnosed by MRI, with normal ligament examination to determine consensus on management and return to activity

ACL reconstructions have evolved to be primarily socket and tunnel reconstructions where grafts are placed and anchored within bone tunnels. Anatomic ACL reconstructions have been recommended to have up to four different tunnels for graft placement. This presentation will focus on the evidence on preclinical and clinical studies on the effect of tunnel length on ACL reconstructions. We will also present our results on a comparative matched cohort study on tradition versus short socket ACL reconstructions using quantitative MR analysis.

Geoffrey Baer1, Naoaki Ito1, Yi-Chung Lin2, Jack A. Martin1, Stephanie A. Kliethermes1, Silvia S. Blemker3, David A. Opar2, Bryan C. Heiderscheit1*; HAMIR Consortium Investigators 1University of Wisconsin – Madison, Department of Orthopedics and Rehabilitation, Madison, WI, USA 2Australian Catholic University, School of Behavioural and Health Science, Fitzroy, VIC, Australia 3Springbok Analytics, Charlottesville, VA, USA Abstract: Athletes after anterior cruciate ligament reconstruction (ACLR) are known to present with atrophied knee extensor muscles and altered knee joint biomechanics during walking and running gait. While these characteristics have been extensively studied in research labs, data from a homogenous cohort (such as division 1 American football athletes) using methods that are clinically feasible to implement as part of routine testing in an athletic setting have not been collected. Traditionally, time constraints in Magnetic Resonance Imaging (MRI) scan times and 3D motion capture, in addition to post-processing time and efforts, have limited our ability to collect this data. The scale of data collected have also been limited due to technological and logistical constrains, such as MRI scans focused on the thigh (versus the whole lower extremity), or running biomechanics during comfortable running speeds (versus full effort sprints). Technological advancements in MRI muscle volume analyses driven by artificial intelligence (Springbok Analytics) and improvements in musculoskeletal modeling algorithms using Inertial Measurement Units (IMUs) have made it possible for our multi-center prospective cohort study funded by the NFL, Hamstring Injury (HAMIR) Index: A Framework for Injury Mitigations Strategies Through Innovative Imaging, Biomechanics, and Data Analytics (ClinicalTrials.gov ID: NCT05343052), to collect such comprehensive data. The presentation will focus on preliminary findings in full lower body (lumbar through ankle musculature) muscle volume distributions, and knee biomechanical asymmetries present during full effort sprinting, in a sub-cohort of athletes enrolled in the study with a history of ACLR. Future directions and the potential application of findings from this large-scale prospective cohort study to impact clinical practice and athlete care will also be discussed.

double blind study of BFR in knee ligament surgery

Background: Our experience with patella instability over 13 years and 640 knees offers clinically useful observations. The purpose of this study was to determine the rates of intra articular pathology identified at the time of arthroscopy which was not identified on preoperative MRI. Also, MPFL Reconstruction can use anchors or drilled tunnels for graft attachment to the patella. Safety and effectiveness of each has not been established with a large case series. Methods: All patients undergoing MPFL reconstruction at our institution between 2010 and 2023 were identified. Operative reports, preop MRI reports, incidence of recurrent instability, and patellar fracture were identified. MRI findings were discordant from arthroscopic findings if a lesion prompted a procedure to address it. Results: 172 patients (34%) had a discordant finding at the time of arthroscopy as compared to preoperative MRI requiring an additional surgical procedure. These resulted in 75 loose body removals, 74 shaving chondroplasties, 16 meniscectomies, 3 microfractures, 3 osteochondral fragment ORIFs, and 2 meniscal repairs. Regarding patella graft fixation, 342 knees (53.9%) were included in the Tunnel group, whereas 293 knees (46.1%) were included in the Anchor group. There was one patellar fracture (0.3%) in the Tunnel group and none in the Anchor group (p=1.0). There was a significantly decreased rate of recurrent instability for the Tunnel group (n = 7, 2.0%) compared to the Anchor group (n= 15, 5.1%; p = 0.035). Conclusion: Greater than 1/3 of patients had pathology identified which required intervention that was not reported on a preop MRI, highlighting the importance of diagnostic arthroscopy in the treatment of patellar instability. Furthermore, two (3.2 mm), short, oblique patellar tunnels with looped graft is a safe and efficacious for MPFL-R, while also conferring cost savings.

Introduction: Quadriceps angle (Q-angle) measurements estimate the lateral force vector of the knee extensor mechanism and have traditionally been used for clinical evaluation and surgical planning in patients with recurrent patellar instability. With the widespread availability of advanced imaging, radiographic measurements such as Tibial Tuberosity – Trochlear Grove (TT-TG) distance have become the standard for measuring knee extensor mechanism malalignment in the sagittal plane. In response to reports of poor reliability of Q-angle measurements, Merchant et al. proposed a modified measurement called “Standard Q-Angle” (SQA), which they demonstrated to have strong interrater reliability in a group of normal patients (Merchant 2020). However, SQA has not yet been validated in patients with anatomic risk factors for recurrent patellar instability such as patella alta, trochlear dysplasia and lateralized tuberosity. The purpose of our study was to determine the correlation between SQA and TT-TG distance in patients with recurrent patellar instability. We hypothesized that there would be a positive correlation between SQA and TT-TG distance. Methods: Patients treated by a single surgeon with recurrent patellar instability who had obtained a dynamic 4D CT scan were included in this study. The SQA was measured as described by Merchant (Merchant 2020). Measurements were taken in the clinic, as well as in the operating room after the induction of general anesthesia. All measurements were performed by the senior author (AJC). Utilizing 4D CT scans, the TT-TG, Caton-Deschamps index (CDI), and lateral trochlear inclination (LTI) were measured as previously described. Patella alta was defined as CDI > 1.20, trochlear dysplasia was defined as LTI < 11°, and lateralized tibial tuberosity as TT-TG > 20mm. Mean and standard deviation values were calculated for patient demographic information, and correlation coefficients were calculated to compare SQA with TT-TG distance in both awake and anesthetized patients. The statistical software Stata was utilized for all analyses. Results: Ninety patient knees were included in the study. The mean age was 23 years (±9 years). For the group as a whole, the correlation was statistically significant in anesthetized patients (R2 = 0.152, p = 0.003), but not awake patients (R2 = 0.031, p = 0.098). Statistically significant correlations were seen in both awake (R2 = 0.057, p = 0.048), and anesthetized (R2 = 0.316, p < 0.001) patients with normal patellar height, awake (R2 = 0.381, p < 0.001), and anesthetized (R2 = 0.274, p < 0.009) patients with normal TT-TG distance and anesthetized patients with no trochlear dysplasia (R2 = 0.267, p = 0.001). Correlations were not statistically significant in either awake or anesthetized patients with patella alta, trochlear dysplasia, or Body Mass Index (BMI) > 30, or in anesthetized patients with a lateralized tuberosity. Conclusions: There was a statistically significant correlation between SQA and TT-TG in a group of anesthetized, but not awake, patients with recurrent patellar instability. Correlations were not statistically significant in subgroups of patients with patella alta, trochlear dysplasia, lateralized tuberosity or BMI > 30. SQA measurement may provide useful information, but generally not in the patients with the greatest risk for recurrent instability. Therefore, it remains important to utilize objective radiographic measurements like TT-TG distance to quantify sagittal alignment when planning patellar stabilization surgery.

The structure of the femoral ACL enthesis is complex and a major determinant of ACL function. The variation in its structure suggests that its function may be developmentally determined. An understanding of its complex structure has implications for normal ACL function and the challenges of ACL reconstruction

Biomechanically sound beats pseudo-anatomic MCL reconstruction Andy Williams, Fortius Clinic / Imperial College, London, UK At the 2022 Herodicus Society meeting I presented: ‘Time to stop pretending ligament reconstructions are ‘anatomic’! Better to be honest- biomechanically sound beats ‘pseudo-anatomic’.’ The 2024 presentation summarises work from Imperial College and my almost exclusively pro-sport practice supporting the philosophy presented in 2022 for MCL reconstruction. Our anatomy study findings differ from commonly held views- eg the superficial MCL (sMCL) attaches the center of the medial femoral epicondyle and not posterior to it as is often popularised, and the deep MCL (dMCL) is an oblique structure passing anterodistal from posterior and distal to the sMCL femoral attachment fanning out to a relatively wide tibial attachment, and not just a short ligament parallel and deep to the sMCL (1). Furthermore, our biomechanics studies (2,3) show the dMCL is a very important structure. The dMCL is the primary restraint to ER in 0-30? and then load shares with sMCL into deeper flexion. The posterior oblique ligament (POL) only provides restraint to internal rotation close to full extension and is only rarely of importance. These study findings account for the isolated dMCL lesions in soccer players having ER injury (4), and frequent injury to dMCL associated with ACL rupture (5), as well as having implications for MCL reconstruction. Regarding MCL reconstruction, popular ‘anatomic’ techniques are sometimes fundamentally flawed. Typically, they include grafts to reproduce the sMCL and POL. All but one (6) never include a dMCL component. Biomechanical studies of them justifying their use can be unsound- one of the most popular (7) showed its sMCL graft controlled not only valgus but also ER, despite having no dMCL component- the results of the lab study reflect the fact that in the specimens tested the native dMCL was not cut before nor after sMCL reconstruction- no wonder it seemed to control ER when the primary restraint to ER remained intact! Testing this popular technique in cadavers with MCL division including cutting the dMCL shows the technique does not control ER at all (8). Adding a dMCL component restores ER control in our studies (8,9,10). Finally, with regard to MCL reconstruction, cadaveric study (10) data showing excellent results justify a non-anatomic short isometric construct MCL reconstruction (11) to protect anatomy restoration by suture techniques, repairing torn structures in acute injuries and re-tensioning of the components of the MCL in chronic cases. This technique is easy and reproducible and rarely requires additional POL. To make it even more controversial a polyester graft is used! Nevertheless, good clinical outcomes data in elite athletes supports this technique’s efficacy and safety (12). The POL is grossly overrated! The only indication for its reconstruction is in cases of PCL + MCL injury to control posteromedial rotatory instability, or excess hyperextension associated with MCL injury. Reconstructing the POL as part of an MCL reconstruction with concomitant ACL reconstruction in anteromedial rotatory instability is not easy, and is pointless in most cases, as well as illogical! The POL is aligned in the opposite direction to the ACL, whereas the dMCL is parallel to it. Since persisting, and even minor, MCL laxity increases ACL graft re-rupture (13, 14, 15), the need to add MCL reconstruction to ACL reconstruction will likely be more frequent (16) and rather analogous to additional anterolateral procedures. Unlike making the decision to add lateral tenodesis to ACL reconstruction which is somewhat arbitrary, there are very clear clinical signs and MRI appearances which are indications for MCL reconstruction to protect ACL grafts. References: 1 Athwal KK, Willinger L, Shinohara S, et al. The bone attachments of the medial collateral and posterior oblique ligaments are defined anatomically and radiographically. Knee Surg Sports Traumatol Arthrosc. 2020;28(12):3709-3719. 2 Willinger L, Shinohara S, Athwal KK, Ball S, Williams A, Amis AA. Length change patterns of the medial collateral ligament and posterior oblique ligament in relation to their function and surgery Knee Surg, Sports Traumatol, Arthrosc 2020;28:3720-3732. 3 Ball S, Stephen JM, El-Daou H, Williams A, Amis AA. The medial ligaments and the ACL restrain anteromedial laxity of the knee. Knee Surg Sports Traumatol Arthrosc. 2020;28(12):3700-3708. 4 Narvani A, Mahmud T, Lavelle J, Williams A. Injury to the proximal deep medial collateral ligament: a problematical subgroup of injuries. J Bone Jt Surg (Br) 2010;92:949-953. 5 Willinger L, Balendra G, Pai V, et al. High incidence of superficial and deep medial collateral ligament injuries in 'isolated' anterior cruciate ligament ruptures: a long overlooked injury. Knee Surg Sports Traumatol Arthrosc. 2022;30(1):167-175. 6 Kim MS, Koh IJ, In Y. Superficial and deep medial collateral ligament reconstruction for chronic medial instability of the knee. Arthrosc Tech. 2019;8(6):e549-e554. 7 LaPrade RF, Wijdicks CA. Surgical technique: development of an anatomic medial knee reconstruction. Clin Orthop Relat Res. 2012;470(3):806-814 8 Miyaji N, Holthof SR, Bastos RPS, et al. A Triple-Strand Anatomic Medial Collateral Ligament Reconstruction Restores Knee Stability More Completely Than a Double-Strand Reconstruction: A Biomechanical Study In Vitro. Am J Sports Med. 2022;50(7):1832-1842. 9 Miyaji N, Holthof SR, Ball SV, Williams A, Amis AA. Medial collateral ligament reconstruction for anteromedial instability of the knee: a biomechanical study in vitro. Am J Sports Med 2022;50:1823-1831. 10 Jobe Shatrov, Petra Bonacic-Bartolin, Sander R Holthof, Andy Williams, Simon V Ball, and Andrew A Amis. A Comparative Biomechanical Study of Alternative Medial Collateral Ligament Reconstruction Techniques. Am J Sp Med 2024 – in press 11 Borque KA, Ball S, Sij E, et al. A ‘short isometric construct’ reconstruction technique for the medial collateral ligament of the knee. Arthrosc Tech 2023;12(2):e167-e171. 12 Borque KA, Jones M, Balendra G, Willinger L, et al. High return to play rate following treatment of multiple-ligament knee injuries in 118 elite athletes. Knee Surg Sports Traumatol Arthrosc 2022; 30(10):3393-3401. 13 Ahn JH, Lee SH. Risk factors for knee instability after anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2016;24(9):2936-2942. 14 Alm L, Krause M, Frosch KH, Akoto R. Preoperative medial knee instability is an underestimated risk factor for failure of revision ACL reconstruction. Knee Surg Sports Traumatol Arthrosc. 2020;28(8):2458-2467. 15 Svantesson E, Hamrin Senorski E, Alentorn-Geli E, et al. Increased risk of ACL revision with non-surgical treatment of a concomitant medial collateral ligament injury: a study on 19,457 patients from the Swedish National Knee Ligament Registry. Knee Surg Sports Traumatol Arthrosc. 2019;27(8):2450-2459. 16 Williams A, Becker R, Amis AA. The medial collateral ligament: the neglected ligament. Knee Surg Sports Traumatol Arthrosc 2020;28:3698–3699.

This is a study of Division 1 collegiate athletes from the PAC-12 conference.

Presented are results of 1021 patients at 2 years after surgery in the MOON Shoulder Instability Cohort which demonstrate interesting findings related to factors that predict patient reported outcomes (PROs). Is it recurrence of dislocation or subluxation, repeat surgery, or other variables such as psychological factors?

Submission is description of the assessment and preliminary data, primarily for shoulder instability cases.

Jarret Woodmass, Sheila McRae, Peter Lapner, Ivan Kamikovski, Jason Old, Jon Marsh, Ben Jong, Greg Stranges, Jamie Dubberley Treny Sasyniuk, Peter MacDonald 1Orthopaedic Surgery, Pan Am Clinic, Winnipeg MB 2Department of Surgery, Section of Orthopaedics, University of Manitoba, Winnipeg, MB 3Pan Am Clinic Foundation, Winnipeg, MB 4The Ottawa Hospital, Ottawa, ON ABSTRACT Background: A multi-center, double-blinded randomized controlled trial comparing isolated Bankart repair (NO REMP) to Bankart with remplissage (REMP) reported benefits of remplissage in reducing recurrent instability at two-years post-operative. The ongoing benefits beyond this time point had yet to be explored. Purpose: The purpose of the current study was to compare medium-term (3 to 9 years) outcomes of these previously randomized patients (NO REMP or REMP) for the management of recurrent anterior glenohumeral instability. Failure rate, overall recurrent instability, and re-operation were examined. Study Design: Randomized Controlled Clinical Trial Methods: Recruitment and randomization for the original randomized trial took place between 2011 and 2017. In 2020, participants were contacted by telephone and asked a series of standardized questions regarding ensuing instances of subluxation, dislocation, or re-operation on their study shoulder. “Failure” was defined as a re-dislocation and “overall recurrent instability” was defined as a re-dislocation or two or more subluxations. Descriptive statistics, relative risk, and Kaplan-Meier survival curve analyses were performed. Results: One-hundred and eight participants were randomized of which 50 in the NO REMP group and 52 in the REMP group were included in the analyses in the original study. The mean number of months from surgery to final follow-up was 49.3 and 53.8 for the NO REMP and REMP group, respectively. Failure rates were 22% (11/50) in the NO REMP group versus 8% (4/52) in the REMP group. Rates of overall recurrent instability were 30% (15/50) in the NO REMP group versus 10% (5/52) in the REMP group. Survival curves were significantly different favouring REMP in both scenarios. Conclusion: For the treatment of traumatic recurrent anterior shoulder instability with a Hill-Sachs lesion and subcritical glenoid bone loss (<15%), a significantly lower rate of overall postoperative recurrent instability was observed with arthroscopic Bankart repair and remplissage than isolated Bankart repair at medium-term follow-up (mean of four years). This finding was also observed in patients at high-risk for re-injury based on Hill-Sachs size and contact sport. Patients who did not receive a remplissage failed (re-dislocated) earlier and had a higher rate of revision/re-operation than those who received a concomitant remplissage. Key Terms: anterior shoulder instability; remplissage; Bankart repair; arthroscopy; long-term What is known about the subject: Arthroscopic Bankart repair with concomitant remplissage has demonstrated early promise in reducing postoperative recurrent instability when compared to Bankart alone, however its effectiveness in preventing failure long-term remains unclear.

Improved outcomes after a combined Bankart repair and remplissage have been previously reported in patients presenting with off-track (engaging) Hill-Sachs lesions. However, whether these benefits hold for patients with on-track (non-engaging) lesions is unknown. Thus, the aim was to examine recurrent instability, return to sport and range of motion outcomes upon comparison of an isolated Bankart repair to those augmented with a remplissage in patients with on-track (non-engaging) Hill-Sachs.

This lecture will describe some novel arthroscopic techniques in addressing glenoid and humeral head bone loss in the patient with shoulder instability. We will describe in detail 'remplissage plus' as well as autologous cancellous grafting of the anterior glenoid.

I will present the concept of central HAGL defects - rents in the humeral attachment between intact anterior and posterior bands of the IGHL. I will present my preferred surgical treatment for this of a glenoid-based capsulorrhaphy with case presentations and biomechanical data to support this approach. I can provide an abstract if that form is preferred.

Purpose: To retrospectively evaluate outcomes following revision surgery for failed arthroscopic Bankart repair and observe the effect on how pre-operative injury characteristics on post-operative outcomes after revision surgery in the competitive athlete population. Methods: Patients who had undergone intervention with revision surgery after a previously failed arthroscopic Bankart repair between 2000 and 2014 were retrospectively reviewed. The type of revision surgeries included revision arthroscopic Bankart repair (12 patients, 15%), open Bankart repair (9 patients, 11.3%), Latarjet procedure (30 patients, 37.5%) and DTA (27 patients, 33.8%). Patients were evaluated with the American Shoulder and Elbow Society score (ASES), Western Ontario shoulder instability index (WOSI), and single numerical assessment evaluation score (SANE) at a minimum of two years after surgery. Demographic and intraoperative findings as a percentage of glenoid bone loss (GBL), Hill-Sachs lesions (HSL), labral and capsule pathologies, and complications were also reported. Differences among groups were analyzed using the Chi-square and Kruskal-Wallis’s tests. The post hoc tests used the Mann-Whitney U test to detect significant pairwise differences. Results: A total of 78 patients (97.4% male) with a median age of 25.9 years (18.2 – 49.3) and a minimum follow-up of 2 years were included. The revision arthroscopic Bankart and open Bankart groups had statistically lower ASES, SANE, and WOSI scores than the Latarjet and DTA groups (p<0.001). In addition, there was a significant difference in ASES score between patients who presented with failure of arthroscopic stabilization and GBL < 25% (91) and > 25% (94), with a p-value of 0.035. However, there was no significant difference in subjective outcomes (SANE and WOSI) between the three different groups of GBL (p=0.069-0.438). There was also no significant difference in the post-revision functional outcomes between differences in the size of HSL, labral and capsule pathologies. Conclusions: Patients who underwent revision open anatomic glenoid reconstruction as Latarjet procedure or DTA showed higher functional outcomes than soft tissue stabilization procedures after failed arthroscopic Bankart repair in the competitive athlete population. Additional work is needed to validate the outcomes and define the best treatment options in this high-risk population.

In biomechanical studies, suture tapes have demonstrated improved load to failure and tissue tear-through for labral repair compared to suture, suggesting that a tape construct in labral repair may reduce failure rates. We performed a retrospective cohort study of active duty servicemembers who underwent arthroscopic shoulder stabilization performed by three fellowship-trained sports surgeons at a single high-volume military facility from 2010-2020. Based on the purported benefits of tape constructs, the surgeons at this facility transitioned to use of suture tape in 2015. We included all patients who underwent isolated anterior or posterior or combined labral repair. We excluded all patients who underwent superior labral repair or with follow-up less than two yearsn total we identified 448 arthroscopic stabilization procedures (211 anterior, 79 posterior, and 158 combined anterior/posterior labral repairs). We excluded all patients undergoing superior labral repair (27 anterior, 23 posterior, and 27 combined) and then further excluded patients with less than 2 years follow-up (21 anterior, five posterior, and 21 combined), leaving 163 anterior, 51 posterior, and 110 combined procedures for analysis. We performed multivariate logistic regression to determine factors associated with higher likelihood of failure after anterior (Table 2) and combined (Table 3) repairs. Labral tape was associated with a lower chance of failure for anterior repairs (p=0.041). There was a similar trend that did not reach significance after combined repairs (p=0.085). Because the failure event rate was zero after posterior repair performed with labral tapes, coefficients and confidence intervals were unable to be calculated and this multivariate analysis was not performed. In addition to previously established risk factors for failure following arthroscopic stabilization procedures, use of suture tape was protective against failure in a young, high-demand military population.

2023-2024 Traveling Fellowship Report

2023-2024 Traveling Fellowship Report

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