Platelet rich plasma and anterior cruciate ligament repair: A new frontier, or a short term adjunct.

What's New in Sports Medicine.

Osseous Deficits After Anterior Cruciate Ligament Injury and Reconstruction: A Systematic Literature Review With Suggestions to Improve Osseous Homeostasis

Is the anterolateral ligament the smoking gun to explain rotational knee laxity or just vaporware?

Background: The effect of platelet-rich plasma (PRP) on the risk of meniscal repair failure is unclear. Current evidence is limited to small studies without comparison between isolated repairs and meniscal repairs with concomitant anterior cruciate ligament (ACL) reconstruction. It is also unclear whether the efficacy of PRP differs between preparation systems in the setting of meniscal repair. Purpose: (1) To determine whether intraoperative PRP affects the risk of meniscal repair failure. (2) To determine whether the effect of PRP on meniscal failure risk is influenced by ACL reconstruction status or by PRP preparation system. Study Design: Cohort study; Level of evidence, 3. Methods: The study entailed 550 patients (mean ± SD age, 28.8 ± 11.2 years) who underwent meniscal repair surgery with PRP (n = 203 total; n = 148 prepared with GPS III system, n = 55 prepared with Angel system) or without PRP (n = 347) and with (n = 399) or without (n = 151) concurrent ACL reconstruction. The patients were assessed for meniscal repair failure within 3 years. The independent effect of PRP on the risk of meniscal repair failure was determined by multivariate Cox proportional hazards modeling with adjustment for age, sex, body mass index, ACL status, tear pattern, tear vascularity, repair technique, side (medial or lateral), and number of sutures or implants used. Results: Failures within 3 years occurred in 17.0% of patients without PRP and 14.6% of patients with PRP (P = .60) (Angel PRP, 15.9%; GPS III PRP, 14.2%; P = .58). Increased patient age was protective against meniscal failure regardless of ACL or PRP status (per 5-year increase in age: adjusted hazard ratio [aHR], 0.90; 95% CI, 0.81-1.0; P = .047). The effect of PRP on meniscal failure risk was dependent on concomitant ACL injury status. Among isolated meniscal repairs (20.3% failures at 3 years), PRP was independently associated with lower risk of failure (aHR, 0.18; 95% CI, 0.03-0.59; P = .002) with no difference between PRP preparation systems (P = .84). Among meniscal repairs with concomitant ACL reconstruction (14.1% failures at 3 years), PRP was not independently associated with risk of failure (aHR, 1.39; 95% CI, 0.81-2.36; P = .23) with no difference between PRP preparation systems (P = .78). Conclusion: Both PRP preparations used in the current study had a substantial protective effect in terms of the risk of isolated meniscal repair failure over 3 years. In the setting of concomitant ACL reconstruction, PRP does not reduce the risk of meniscal repair failure.

Techniques in Double-Bundle Anterior Cruciate Ligament Reconstruction: As Simple as ABC, or Putting the Cart Before the Horse?

Biologic agents to optimize outcomes following ACL repair and reconstruction: A systematic review of clinical evidence.

Static patellofemoral alignment in anterior cruciate ligament deficient knees; a retrospective analysis with magnetic resonance imaging

Over and over again, we read about new techniques to reconstruct the anterior cruciate ligament (ACL). In most papers, the authors present interesting and well-thought new surgical techniques. In recent years, novel technical innovations have been discussed over and over again and many of them are sound and improve the patient care, for instance the recent knowledge and new understanding about anatomical ACL reconstruction. As we all know, injuries to the ACL are frequently occurring, especially in young athletes. In fact, an ACL injury is the single most common and serious ligament injury in the body and by far the most costly. There are still several outstanding questions when it comes to diagnostic evaluation and treatment of ACL injuries. Sometimes we are far too concerned with the surgical techniques and pay too little attention to the patient. Of course, the patient should be in the center all the time. In this issue of the journal, Decker et al. [1] report on new insights into ACL deficiency and reconstruction through assessment of knee kinematic variability in terms of nonlinear dynamics. In other words, we should be more aware of the possibility of restoring normal knee kinematics and gait. This may happen through rehabilitation or surgery, or preferably both. The authors state that it is critical to better understand neuromuscular function both after an ACL rupture and reconstruction as well and utilize nonlinear measures as an important component of assessment after ACL reconstruction. The assessment of kinematic variability using nonlinear dynamics can provide important understanding of knee function after ACL injury and after ACL reconstruction. This is of much greater importance than we have previously considered, i.e., not only to understand the surgical anatomy, but also the total function of the entire knee joint, the entire lower limb, and the entire patient. The authors state that it is important to determine the reliability of nonlinear measures in patients who have sustained an ACL injury, after ACL reconstruction and finally in order to delineate which surgical technique(s) are related to the best outcome in terms of normal (or near normal) nonlinear values. In other words, we need to pay much more attention to normal mechanics and abnormal neurophysiological issues in patients with ACL injuries. We need to understand the importance of normal knee kinematics during sports activities in ACL-deficient knees and after ACL reconstruction, for instance during gait [2]. This might—in the future—enable us understand some of the mechanisms behind the development of osteoarthritis after an ACL injury and reconstruction. We might also gain more insights into why an ACL reconstruction does not automatically prevent the development of osteoarthritis of the injured knee.

Background: Recent biomechanical studies have demonstrated that an extra-articular lateral knee structure, most recently referred to as the anterolateral ligament (ALL), contributes to overall rotational stability of the knee. However, the effect of anatomic ALL reconstruction (ALLR) in the setting of anterior cruciate ligament (ACL) reconstruction (ACLR) has not been biomechanically investigated or validated. Purpose/Hypothesis: The purpose of this study was to investigate the biomechanical function of anatomic ALLR in the setting of a combined ACL and ALL injury. More specifically, this investigation focused on the effect of ALLR on resultant rotatory stability when performed in combination with concomitant ACLR. It was hypothesized that ALLR would significantly reduce internal rotation and axial plane translation laxity during a simulated pivot-shift test compared with isolated ACLR. Study Design: Controlled laboratory study. Methods: Ten fresh-frozen cadaveric knees were evaluated with a 6 degrees of freedom robotic system. Knee kinematics were evaluated with simulated clinical examinations including a simulated pivot-shift test consisting of coupled 10-N·m valgus and 5-N·m internal rotation torques, a 5-N·m internal rotation torque, and an 88-N anterior tibial load. Kinematic differences between ACLR with an intact ALL, ACLR with ALLR, and ACLR with a deficient ALL were compared with the intact state. Single-bundle ACLR tunnels and ALLR tunnels were placed anatomically according to previous quantitative anatomic attachment descriptions. Results: Combined anatomic ALLR and ACLR significantly improved the rotatory stability of the knee compared with isolated ACLR in the face of a concurrent ALL deficiency. During a simulated pivot-shift test, ALLR significantly reduced internal rotation and axial plane tibial translation when compared with ACLR with an ALL deficiency. Isolated ACLR for the treatment of a combined ACL and ALL injury was not able to restore stability of the knee, resulting in a significant increase in residual internal rotation laxity. ALLR did not affect anterior tibial translation; no significant differences were observed between the varying ALL conditions with ACLR except between ACLR with an intact ALL and ACLR with a deficient ALL at 0° of flexion. Conclusion: In the face of a combined ACL and ALL deficiency, concurrent ACLR and ALLR significantly improved the rotatory stability of the knee compared with solely reconstructing the ACL. Clinical Relevance: Significant increases in residual internal rotation and laxity during the pivot-shift test may exist in both acute and chronic settings of an ACL deficiency and in patients treated with isolated ACLR for a combined ACL and ALL deficiency. For this subset of patients, surgical treatment of the ALL, in addition to ACLR, should be considered to restore knee stability.

What's New in Sports Medicine.

Objectives: The local and systemic immune responses to anterior cruciate ligament (ACL) injury and ACL reconstruction likely have substantial effects on graft-to-bone healing and patient recovery; however, the immune cell profile following ACL injury and reconstruction has not been well-characterized. The primary aim of the study was to evaluate the local and systemic immune response to ACL injury and reconstruction using a murine ACL reconstruction model. The secondary aim of the study was to evaluate the impact of postoperative physical activity on the immune cell profile. Methods: Following IACUC approval (IACUC approval number: 2019-0034), fifty-five 11-week-old male C57BL/6 mice were randomized to one of 3 groups: (1) closed ACL rupture only (“closed” group, n = 15), (2) closed ACL rupture followed by immediate ACL reconstruction (“immediate” group, n = 19), or (3) closed ACL rupture followed by delayed ACL reconstruction at 7-days post-injury (“delayed” group, n = 15). Thirty-three of the mice were sacrificed at 10 days post-injury or post-surgery, 16 of the mice were sacrificed at 3 days, and 6 mice were sacrificed as uninjured controls. For the group of mice sacrificed at 10 days, half of the mice underwent 1 week of daily treadmill running for 40 minutes (n = 6 in the immediate group, n = 6 in the delayed group, and n = 6 in the closed group), with the other half remaining as a free cage activity group (n = 6 in the immediate group, n = 6 in the delayed group, and n = 3 in the closed group). Draining ipsilateral iliac lymph nodes (iLN) to assess local immune responses and spleens to assess systemic responses were harvested and processed for flow cytometry. Unpaired, two-tailed t-tests were used to evaluate for differences in total lymph node cellularity between groups. In addition, the OsteoArthritis Research Society International (OARSI) scoring system was used to evaluate the degree of articular cartilage degeneration in each mouse. Results: Compared to uninjured normal mice, mice undergoing closed ACL rupture with or without ACL reconstruction had increased total iLN cellularity. The greatest increase in cellularity (over 8-fold) was observed in the 10-day immediate ACL reconstruction group with postoperative physical activity having little effect. There was a similarly large increase in cellularity in the 10-day delayed group only observed in mice that underwent daily treadmill running (Figure 1, p < 0.001). These differences were reflected in the absolute B cell and CD4+, CD8+, and T regulatory cell counts. Monocyte, macrophage, resident dendritic cell (DC), migratory DC, and neutrophil counts also mirrored this trend. In contrast, differentiated plasma cells (PCs) were increased only in the treadmill running groups regardless of surgical timing. Compared to normal uninjured mice, total spleen cellularity was increased only in 10-day immediate, and 10-day delayed running groups. Splenic monocyte and neutrophil counts were increased in these groups as well. The B/T cell ratio was elevated in only the 3-day groups. Conclusions: Postoperative physical activity in the setting of delayed ACL reconstruction is associated with increased local and systemic immune responses, reflecting either increased inflammation to clear the site of injury or an aberrant, prolonged inflammatory response. Postoperative physical activity played a smaller role in the setting of immediate ACL reconstruction. We hypothesize that excessive physical activity may delay or prevent resolution of the post-injury inflammatory process. The greater increase in immune response in the delayed ACL reconstruction group may be due to further stimulation of inflammation secondary to knee instability following the ACL injury. While inflammation is part of the normal response to injury, unresolved or excessive inflammation may impair graft healing due to stimulation of fibrosis and may also contribute to the development of PTOA. Our ongoing histologic, gene expression, and biomechanical studies will provide further insight into the biological relevance of such immune responses.

A Call for More Studies Evaluating Posttraumatic Knee Osteoarthritis in Patients Undergoing Combined Anterior Cruciate Ligament Reconstruction and Lateral Extra-Articular Stabilization

Surgical Reconstruction After Anterior Cruciate Ligament Injury Is Associated With Reduced Odds of Future Total Knee Arthroplasty at Mid- to Long-Term Follow-Up.

Objectives:Anterior cruciate ligament (ACL) tears are one of the most common ligamentous injuries of the knee. While many advances have been made in both surgical technique and rehabilitation protocols, it still remains a very serious athletic injury. In recent years, a few high-profile athletes have returned to an elite sport performance level relatively quickly after ACL reconstruction, but previously published literature suggests otherwise. The purpose of this study is to evaluate a college athlete's perception and understanding of ACL injury and subsequent reconstruction.Methods:During pre-participation physicals, a total of 157 surveys were prospectively administered to athletes at a single NCAA Division II university, all of which were returned. Consent was obtained prior to survey administration. The surveys, consisting of sixteen questions, were designed to evaluate the athletes’ knowledge of ACL injury, anatomy, and recovery from surgery. In addition, basic demographic information was obtained including the participants’ source of ACL knowledge. Statistical analysis is pending.Results:The average age of participants was 20.1 years (Range: 18-23). Football, soccer and baseball were the most represented sports among participants, but a wide variety were present. Of the 157 surveys administered, 106 of participants (68%) knew that the ACL was a ligament. The majority of participants (63%) thought it would take 8-12 months to return to sport after an injury, but 31% said an athlete could return in less than 6 months (Range: 2 to 15 months). On average, the participants thought 64% of athletes could return to play in their sport after an ACL injury and reconstruction, but only 45% could return to their previous level of play. However, several participants (8%) believed greater than 80% of athletes could return to their previous level of play after an ACL reconstruction. Only 11% of respondents knew that a knee brace cannot prevent ACL injury. Most participants (82%) said that if they had an ACL injury they would undergo reconstructive surgery. Only 26% of participants knew that an athlete with an ACL injury was at an increased risk for an injury to their contralateral ACL. Furthermore, about half of the participants (54%) thought that on-field performance would not improve following an ACL injury and reconstruction. The most common source of participants’ knowledge of ACL injury was from a friend or family member (71%). Far fewer participants gained at least some of their knowledge from the internet (32%), television (27%) or their physician/surgeon (29%).Conclusion:This is the first study, to our knowledge, to assess the perceptions of high-level athletes with regards to ACL injury, reconstruction and return to play. This study demonstrates that there is a large amount of variability in college athletes’ perception of ACL injuries. The range of recovery time from surgery was quite large, signifying a knowledge gap among high-level athletes with regard to this very common injury. Orthopaedic surgeons may want to assess and tailor their pre-surgical discussions with a college athlete to the individual's knowledge of ACL injury and reconstructions, so that realistic pre-surgical expectations are set. However, the benefits of this approach warrant further investigation.

IntroductionAnterior cruciate ligament (ACL) injuries in high-impact contact sports athletes are often treated through surgery. Recently, conservative treatment of ACL injuries in athletes using autologous biotherapy such as platelet-rich plasma (PRP) has been reported. We report two cases of aggressive conservative treatment with PRP therapy for contact athletes.Presentation of caseCase 1. A 23-year-old male rugby player with a preinjury Tegner score of 9 underwent three PRP treatments following an ACL injury and returned to preinjury levels of play 4 months postinjury. The pivot shift test had improved to grade 0 at the last follow-up. Case 2. A 34-year-old male mixed martial arts fighter with a preinjury Tegner score of 9 underwent five PRP treatments following an ACL injury and returned to his preinjury play level 3.5 months postinjury. Both contact athletes returned to competition early and continued to compete without losing stability at the final follow-up. Moreover, their functional score exceeded the median score for athletes after ACL reconstruction, suggesting satisfactory performance.DiscussionAntiinflammatory cytokines and growth factors in PRP may promote graft maturation and alter the natural history of remodeling, resulting in earlier and firmer graft maturation, improving both the duration and quality of the healing process.ConclusionTwo high-impact sports athletes with ACL injuries were treated with aggressive conservative therapy using PRP and returned early to their preinjury play level.