What's New in Sports Medicine.

Abstract

This update represents a summary of the best available published literature in the subspecialty of sports medicine, published primarily between October 2019 and September 2020. Articles have been selected on the basis of quality and topic and provide an informative base of literature that supports clinical and surgical decision-making in sports medicine. Knee Anterior Cruciate Ligament (ACL) The ACL remains at the forefront of sports medicine research, and studies assessing the most effective methods of ACL reconstruction continue to influence surgical decision-making. Although this surgical procedure has been successfully performed for over 4 decades, the debate over optimal graft choice in the athletic patient population persists. One 6-year prospective study (using the MOON [Multicenter Orthopaedic Outcomes Network] database) compared the revision rates after primary ACL reconstruction using bone-patellar tendon-bone (BTB) autograft or hamstring tendon autograft in a population of high school and college-aged athletes1. In this cohort of 770 patients with a median age of 17 years, 64% of patients received a BTB autograft and 36% received a hamstring tendon autograft during the primary reconstruction. At the 6-year follow-up, 9.2% (n = 71) of patients underwent an ipsilateral revision ACL reconstruction and, within this cohort, the odds for ACL graft revision were 2.1 times higher for patients receiving a hamstring autograft compared with those receiving a BTB autograft. More specifically, 7.1% (n = 35) of the BTB autograft group and 13.0% (n = 36) of the hamstring autograft group required revision ACL reconstruction within the study period. The incidence of contralateral knee ACL reconstruction was 11.2% among the entire population, although, notably, no significant difference was found between graft choices. In addition to autograft type, high-grade knee laxity and younger age were determined to be significant predictors of ipsilateral revision ACL reconstruction. Separate from the influence of these other factors, hamstring autograft independently increased the risk of revision by 5% to 10% in otherwise low-risk patients1. In an analysis of the New Zealand ACL Registry, Rahardja et al.2 evaluated 7,155 patients undergoing primary ACL reconstruction (mean age, 30 years) and published a report on the rates of revision ACL reconstruction and contralateral ACL reconstruction over a 4-year period. Similar to the article from the MOON Knee Group1, Rahardja et al. found that the use of a patellar tendon graft reduced the risk of graft rupture, although they also noted that the patellar tendon graft choice was associated with higher rates of contralateral ACL reconstruction, highlighting the importance of proper rehabilitation and injury prevention prior to returning to activity2. Adding an additional soft-tissue procedure to augment primary ACL reconstruction, including lateral extra-articular tenodesis or anterolateral ligament (ALL) reconstruction, has increased in popularity. Until recently, the evidence supporting ACL reconstruction augmentation has been limited. In 2020, some results from the STABILITY study were published, including the initial 2-year outcomes data comparing ACL reconstruction with single-bundle hamstring tendon autograft either with or without lateral extra-articular tenodesis3. In this multicenter, prospective, randomized clinical trial (RCT) of 618 patients (48% male; mean age, 19 years), the authors reported an 11% graft failure rate in the ACL reconstruction group compared with 4% in the group that underwent ACL reconstruction with lateral extra-articular tenodesis (p < 0.001), with a similar level of sports activity between the groups at 2 years as determined via the Marx Activity Rating Scale (p = 0.11). The authors concluded that adding lateral extra-articular tenodesis to ACL reconstruction (single-bundle hamstring autograft) results in a significantly and clinically important reduction in ACL reconstruction failure at 2 years following the surgical procedure. Interestingly, in a second publication analyzing the same cohort, the authors found that the addition of lateral extra-articular tenodesis to ACL reconstruction was associated with slightly increased pain scores, reduced self-reported function scores, and reduced quadriceps strength early on (up to 6 months) following the surgical procedure, but that all differences were similar to those of patients who underwent ACL reconstruction without lateral extra-articular tenodesis at 1 year postoperatively4. In addition, at 6, 12, and 24 months, there was no difference in the hop test limb symmetry index between the 2 groups. In addition to better understanding failure rates and contralateral injury rates, the ability to return to sport as a function of ACL reconstruction graft choice continues to be of great interest to sports medicine surgeons. A systematic review and meta-analysis was performed to evaluate differences between BTB and hamstring tendon autografts with respect to return-to-sport outcomes5. Twenty articles with 2,348 athletes were included, with an overall return-to-sport rate of 73.2%. Within the population of patients who received a BTB autograft (n = 610), the return-to-sport rate was 81.0%, with 50.0% returning to preinjury levels of play and a rerupture rate of 2.2%. In comparison, within the population of patients who received a hamstring tendon autograft (n = 1,738), the return-to-sport rate was 70.6%, with 48.5% returning to preinjury levels of play and a rerupture rate of 2.5%. When narrowing their analysis to Level-I and Level-II studies only, the authors noted the same pattern, with higher return-to-sport rates in the BTB autograft group5. Meniscus As our understanding of the impact of meniscectomy on knee health continues to grow, improving outcomes following meniscal repair remains of utmost importance. In a systematic review, Haunschild et al.6 examined the functional and radiographic outcomes of meniscal repair surgical procedures, comparing a platelet-rich plasma (PRP)-augmented repair with a standard technique without augmentation. Of the 5 studies included in their review, 3 studies found no significant differences in outcomes or failures, and 2 studies showed a significant improvement in PRP-augmented repairs at the time of the final follow-up (ranging from 32 to 54 months). In a prospective RCT, second-look arthroscopy was utilized as an assessment tool and showed significantly greater healing when the meniscal repair was augmented with PRP. Of note, Haunschild et al. highlighted the limitations of their included articles, including the heterogeneity of articles with respect to repair technique and PRP preparation. In a 2020 study evaluating outcomes following all-inside arthroscopic techniques for the repair of bucket-handle meniscal tears, Ardizzone et al. performed a systematic review of 15 studies comprising 396 patients undergoing this procedure7. This study showed an overall failure rate of 29.3% at a mean time of 13 months following the surgical procedure, with no significant differences when compared with standard inside-out repairs. Certain specific devices, as well as male sex and longer follow-up duration, were found to be factors associated with failure. As new meniscal repair devices are developed, it remains important to critically analyze outcomes and failure rates in studies such as these. Another hot topic in meniscal surgical procedures centers on posterior meniscal root tears and their association with the development of arthritis, both with and without repair. Bernard et al.8 studied the outcomes of 45 patients with posterior medial meniscal root tears that underwent nonoperative treatment (n = 15), partial meniscectomy (n = 15), or root repair (n = 15). Of the outcomes measured, progression to knee arthroplasty and arthritic progression on radiographs were significantly different between groups, and patient-reported outcomes including the International Knee Documentation Committee (IKDC) and Tegner scores showed no significant differences. Specifically, at a mean follow-up of 74 months, 27% of patients treated nonoperatively progressed to arthroplasty compared with 60% of patients who underwent a partial meniscectomy and 0% of patients who underwent a root repair. Further, the root repair group had less arthritic progression as demonstrated by only a 0.1 change in Kellgren-Lawrence grade (compared with a 1.0 change in the nonoperatively treated group and 1.1 in the partial meniscectomy group)8. In a separate study comparing older patients (>45 years of age) undergoing root repair (medial or lateral root tears) compared with nonoperative treatment, similar results were found. Specifically, in this study of 48 patients followed for a mean of 4.4 years, the repair group showed improved patient-reported outcomes and lower rates of progression to arthroplasty9. Patellofemoral Instability Recurrent lateral patellar instability is a common condition in young athletes, but there remains ambiguity with regard to the most effective treatment, with myriad treatment options. Puzzitiello et al.10 reviewed 51 knees that underwent either isolated medial patellofemoral ligament (MPFL) reconstruction (n = 32) or imbrication and/or repair (n = 19) at a mean follow-up of 59.7 months following the surgical procedure. Overall, the MPFL repair group experienced a significantly higher rate (p = 0.01) of recurrent instability at 36.9% compared with the reconstruction group at 6.3%. Interestingly, the mean Caton-Deschamps Index (CDI) was significantly higher (p = 0.04) in the reconstruction group (1.34) compared with the repair group (1.23); within the MPFL repair group, failures had a significantly higher mean CDI (p = 0.03) at 1.30 compared with nonfailures at 1.18. No significant differences between groups were reported for the rate of return to baseline activity or for the mean postoperative Kujala scores. Overall, the authors concluded that MPFL reconstruction showed improved results compared with MPFL repair, and in patients undergoing MPFL repair, higher patellar height indicated by a higher CDI could be a risk factor for recurrent patellar instability10. Shoulder Rotator Cuff For a variety of reasons, large-to-massive rotator cuff tears are difficult injuries to successfully treat, which has led to a multitude of studies assessing the performance and outcomes of various surgical techniques. Strategies include arthroscopic rotator cuff repair, partial repair, augmentation with patches (i.e., superior capsular reconstruction), tendon transfers, and reverse shoulder arthroplasty. Jeong et al.11 compared clinical and radiographic outcomes between arthroscopic rotator cuff repair with a posterior interval slide and partial repair without a posterior interval slide. Clinical outcomes and retear rates were similar between the groups during the minimum 5-year follow-up period, but patients who underwent the complete repair had larger retear sizes and reduced acromiohumeral intervals compared with patients in the partial-repair group11. This led the authors to conclude that partial repair may be preferable to complete repair in this setting. In a separate study, Lin et al.12 analyzed the differences between 2 clinically successful techniques for reconstructing large and massive rotator cuff tears: graft bridging and superior capsular reconstruction. Improvements in clinical outcomes were observed in both groups, but significantly greater mean differences between preoperative and postoperative scores were observed in the graft bridging group. Further, active rotation with the arm at the side was significantly better in the graft bridging group, but no significant differences were found when assessing other planes of motion. Finally, similar complication rates were observed between the 2 groups: 0.67% for graft bridging and 0.84% for superior capsular reconstruction12. Although many authors focus on the optimal surgical technique for rotator cuff tears, other studies have analyzed if a surgical procedure is even necessary. In a multicenter, Level-II study, Song et al.13 compared 96 patients undergoing nonoperative treatment with 73 patients undergoing a surgical procedure for rotator cuff tears. The authors found that, in the short term (approximately 3 months), patients in the nonoperative group had significantly better outcomes, but over time, surgical patients did better with respect to improvements in American Shoulder and Elbow Surgeons (ASES) scores and Shoulder Pain and Disability Index (SPADI) scores. Specifically, the surgical group was more likely to achieve >50% reduction (improvement) in SPADI scores at 15.5 months and in ASES scores at 24.7 months compared with the nonoperative treatment group. Certainly, more in-depth studies stratifying by the type of tear and the specifics of both nonoperative and operative treatments are warranted. Glenohumeral Instability A growing area of controversy in sports medicine is how to manage patients following a first-time shoulder dislocation event. Although prior literature has suggested surgical stabilization as the treatment of choice for recurrent dislocations, more recently, some surgeons have advocated for surgical management after a single dislocation event. Yapp et al. published long-term outcomes following an RCT of 65 first-time dislocators (≤35 years of age) undergoing either arthroscopic Bankart repair (n = 33) or arthroscopic washout (n = 32) at a minimum of 10 years following the surgical procedure14. The authors found a significantly higher rate of recurrent dislocation (p = 0.002) in the arthroscopic washout group (47%) compared with the arthroscopic Bankart repair group (12%), with better long-term Western Ontario Shoulder Instability Index (WOSI) scores in the arthroscopic Bankart repair group. Overall, the authors believed that these data supported arthroscopic Bankart repair for a first-time dislocator. Acromioclavicular Joint With a shift toward less invasive and increasingly anatomic techniques in managing high-grade acromioclavicular joint separations, Pill et al.15 performed a systematic review evaluating 21 studies using either a double or single clavicle tunnel tendon graft construct and compared outcomes and complications between these methods. The authors also compared the use of autograft with that of allograft for augmentation during acromioclavicular joint reconstruction. The authors found that the double clavicle tunnel technique was used more frequently, but had higher rates of complications compared with the single clavicle tunnel technique. The allograft group had a greater incidence of reoperation, but had lower loss of reduction compared with the autograft group. Notably, complications were high in the entire cohort regardless of the technique or graft used, with an overall reoperation rate of 8% and complication rate of 21.3%. Complications were variable in severity, ranging from clavicle fractures and wound infections to asymptomatic calcification of the coracoclavicular ligaments. Overall, the authors suggested that, based on their findings, minimizing trauma to the clavicle during reconstruction and using an autograft tendon reduce the risk of reoperation15. Another area of growing interest specific to acromioclavicular joint reconstruction centers on the timing of surgical procedures, with a recent renewed interest in early reconstruction. In a 2020 study, Lädermann et al. compared early reconstruction outcomes (mean, 1.1 weeks) with delayed reconstruction outcomes (mean, 84.3 weeks) and found equivalent clinical outcomes, suggesting that early surgical intervention is not truly necessary and reconstruction at a later date remains a good option for many patients16. Long Head of the Biceps Tendon In what is seemingly a never-ending debate on how to manage the pathology of the long head of the biceps tendon, MacDonald et al. performed a prospective, double-blinded randomized controlled trial (RCT) comparing biceps tenodesis (n = 57) with biceps tenotomy (n = 57) at a minimum follow-up of 2 years17. The authors showed no difference in either subjective or objective outcome scores, including cramping, elbow flexion strength, and supination strength. The only significant difference observed between groups was the incidence of a cosmetic Popeye deformity, which was associated with a 3.5 times higher risk after tenotomy compared with tenodesis17. Hip Hip preservation surgery, including both arthroscopic and open techniques, has evolved substantially over the past decade, and in particular over the last several years. Many studies have focused not only on surgical techniques and their associated outcomes, but also on indications for the surgical procedure. In 2020, Dwyer et al.18 performed a meta-analysis of 3 high-quality RCTs comparing the treatment of femoroacetabular impingement with either surgical management (hip arthroscopy) or nonoperative management (physical therapy). The review included a total of 650 patients, with 323 patients randomized to surgical treatment and 327 patients randomized to physical therapy. At the frequency-weighted mean follow-up period of 10 months, postoperative International Hip Outcome Tool-33 (iHOT-33) scores showed greater improvement in the operative group during pooled analysis of all 3 studies. Two studies also used the Hip Outcome Score-Activities of Daily Living (HOS-ADL) and HOS-Sports subscales as outcome measures. Of these studies, 1 showed no significant between-group differences at follow-ups of 1 or 2 years for either scale, but the other showed improved scores on both scales after the surgical procedure compared with physical therapy at the 6-month follow-up. Overall, the authors of the meta-analysis concluded that patients with femoroacetabular impingement treated with hip arthroscopy had significantly superior short-term outcomes compared with physical therapy alone18. When comparing surgical options for femoroacetabular impingement, Nepple et al.19 compared hip arthroscopy and surgical dislocation in a prospective, multicenter cohort study of 256 hips. After propensity-matched analysis, which adjusts for confounding variables and reduces selection bias in nonrandomized studies, no significant differences were observed between groups in patient-reported outcome measures, rate of conversion to total hip arthroplasty, the rate of revision surgical procedures, or overall rates of persistent symptoms at a mean follow-up of 4 years19. Certainly, patient selection plays a role, and surgical decision-making must occur on an individual, case-by-case basis to achieve the results described in these studies. Ankle—Achilles Tendon With increasing interest in the nonoperative treatment of acute Achilles tendon ruptures, there has been a renewed interest in performing studies to better understand which nonoperative treatment techniques are most effective. To that end, Maempel et al.20 conducted an RCT comparing a traditional immobilizing plaster cast with functional walking boot rehabilitation for Achilles tendon injuries. Patients treated with the boot reported better patient-reported outcomes at 6 months compared with patients with the cast, but there was no difference in outcomes at 1 year. The rerupture rate was 7.2% in the boot group and 15.5% in the cast group, but this was not found to be significant. Functional rehabilitation was concluded to be a safe alternative to immobilization for acute Achilles tendon ruptures, with improved early functional outcomes20. In a separate study, Barfod et al.21 performed an assessor-blinded RCT to investigate the safety and efficacy of early controlled motion of the ankle compared with immobilization for 8 weeks for Achilles tendon ruptures. At 1 year after the injury, no differences were observed between groups for any of the outcomes measured, including the Achilles tendon Total Rupture Score, heel-rise work test, Achilles tendon elongation, or rate of rerupture, suggesting that early controlled motion has no benefit for acute Achilles tendon rupture management compared with immobilization21. In another article analyzing nonoperative treatments for Achilles tendon ruptures, the effect of PRP injections was compared with that of placebo injections. In this prospective, double-blinded RCT, patients received 4 total injections (either PRP or saline solution placebo), with the first occurring within 4 days of the injury and subsequent injections at 2-week intervals22. All patients, regardless of treatment group, were treated with a wedged orthosis and weight-bearing as tolerated allowed starting on day 1. The authors reported no difference in the rerupture rate, Achilles tendon Total Rupture Score, heel-rise work, heel-rise height, tendon elongation, calf circumference, or ankle dorsiflexion range of motion between groups at 12 months22. The authors concluded that PRP in nonoperatively treated Achilles tendon ruptures did not result in improved outcomes. Biologics Among the fastest-growing areas of research within sports medicine, orthopaedic surgery, and medicine in general is biologics. In sports medicine, biologic research over the past year has focused primarily on PRP and cellular therapies. Notably, the heterogeneity of biologic preparations, in particular PRP, make evaluating the literature difficult. In 2020, Cavendish et al.23 performed a systematic review and meta-analysis of 16 RCTs or prospective cohort studies to determine the influence of perioperative PRP injections on failure rates after arthroscopic rotator cuff repair for rotator cuff tears. Despite the heterogeneity in PRP preparations across the studies, pooled analysis showed that PRP augmentation resulted in a 25% reduction in the risk of repair failure, including studies of small to medium tears as well as large to massive tears. Further, 6 of the 16 studies showed significant improvements in ≥1 subjective or objective measure associated with intraoperative PRP augmentation23. To evaluate biologics as a nonoperative treatment option for knee osteoarthritis, Tan et al.24 conducted a meta-analysis of 26 RCTs involving a total of 2,430 patients comparing intra-articular injections of PRP and hyaluronic acid. The PRP group experienced significantly better outcomes than the hyaluronic acid group at 3, 6, and 12 months, including improved Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total scores, WOMAC physical function scores, and visual analog scale scores. Further, at 6 and 12 months, patients in the PRP group had significantly better scores on the WOMAC pain, WOMAC stiffness, EuroQol visual analog, and IKDC scales. Overall, PRP was found to be more effective than hyaluronic acid in treating knee osteoarthritis, with both PRP and hyaluronic acid being comparable in safety profiles24. As an alternative to traditional ACL reconstruction in young patients, Murray et al.25 investigated the viability of the bridge-enhanced ACL repair (BEAR) technique to treat complete midsubstance ACL injuries. This method involves the placement of a resorbable protein-based implant that contains autologous blood in the gap between the 2 torn ends of a midsubstance ACL tear, combined with suture repair of the ligament and a suture cinch to reduce the tibiofemoral joint. In this study, 100 patients (median age, 17 years) were randomized to either BEAR (n = 65) or ACL reconstruction with autograft (2 BTB and 33 hamstring), with all patients undergoing the surgical procedure within 45 days of the injury. At the 2-year follow-up, the authors reported no significant difference between groups in the IKDC Subjective Score, the IKDC Objective Score, or anteroposterior knee laxity. The BEAR group experienced significantly greater hamstring muscle strength in comparison with the autograft ACL reconstruction group, and 14% (n = 9) of the BEAR group and 6% (n = 2) of the ACL reconstruction group had a reinjury requiring a second ipsilateral ACL surgical procedure (p = 0.32). Overall, the authors found that the BEAR technique resulted in similar and noninferior postoperative outcomes when compared with autograft ACL reconstruction in this particular patient population25. Upcoming Sports Medicine Events Certainly, given the COVID-19 pandemic, 2020 was a unique year for all of us, and the impact of the COVID-19 pandemic on sports medicine is still evolving. With public health safety restrictions effectively shutting down sports at all levels, the impact of seasons lost on athletes, coaches, parents, industry, hospitals, universities, practices, physicians, and other health-care providers within sports medicine remains unknown. Upcoming sports medicine meetings will focus on the areas described in this article, but also on the impact of COVID-19 on sports medicine as a whole. The American Orthopaedic Society for Sports Medicine (AOSSM) and the Arthroscopy Association of North American (AANA) annual meetings will be held as a combined meeting in Nashville, Tennessee, on July 7 to 11, 2021, with the Biologic Association Annual Summit occurring in tandem. Other societies, including the ASES, the International Cartilage Regeneration & Joint Preservation Society (ICRS), and the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine (ISAKOS), are slated to hold in-person meetings. In addition to topics such as ACL tears, meniscal tears, and rotator cuff tears, discussions on the medical implications of COVID-19 in athletes, elective surgical procedure shutdowns, biologic therapies, overuse injuries, and nonoperative treatments are likely to be featured. Evidence-Based Orthopaedics The editorial staff of JBJS reviewed a large number of recently published studies related to the musculoskeletal system that received a higher Level of Evidence grade. In addition to articles cited already in this update, 8 other articles relevant to sports medicine surgery are appended to this review after the standard bibliography, with a brief commentary about each article to help guide your further reading, in an evidence-based fashion, in this subspecialty area. Evidence-Based Orthopaedics Cheesman Q, DeFrance M, Stenson J, Weekes D, Feldman J, Abboud J, Austin L. The effect of preoperative education on opioid consumption in patients undergoing arthroscopic rotator cuff repair: a prospective, randomized clinical trial-2-year follow-up. J Shoulder Elbow Surg. 2020 Sep;29(9):1743-50. Epub 2020 Jun 9. This was a 2-year follow-up of a 2018 study that showed reduced opioid consumption at a 3-month follow-up after arthroscopic rotator cuff repair with the use of preoperative opioid education. To understand its effect on opioid dependence at 2 years after arthroscopic rotator cuff repair, patients were randomized into a study cohort and a control cohort. The study group had a significantly lower rate of opioid dependence (11.4% compared with 25.7%) and fewer mean prescriptions filled (2.9 compared with 6.3) compared with control patients. Although not found to be significant, fewer pills and fewer morphine milligram equivalents were consumed by study patients than by control patients. Preoperative education on opioid use resulted in long-term benefits and was protective against opioid dependence at 2 years after arthroscopic rotator cuff repair. This study shows the positive impact of preoperative patient education on changing postoperative patient habits, including opioid use, following rotator cuff repair. Davey MS, Hurley ET, Withers D, Moran R, Moran CJ. Anterior cruciate ligament reconstruction with platelet-rich plasma: a systematic review of randomized control trials. Arthroscopy. 2020 Apr;36(4):1204-10. Epub 2020 Jan 25. The investigators reviewed 13 RCTs and completed a meta-analysis on 4 of the studies that involved BTB grafting to evaluate the effectiveness of using PRP concomitantly with ACL reconstruction. Among the 7 studies that performed ACL reconstruction using a hamstring tendon autograft, no clinical improvement assessed through various subjective scores was demonstrated when comparing the PRP group with a control group, but 2 studies observed significantly better magnetic resonance imaging (MRI) findings. In 2 studies, PRP with allograft ACL reconstruction also showed no additional benefits. Finally, meta-analysis of the 4 studies examining PRP with BTB reconstruction also showed no improvements on functional outcomes or in postoperative visual analog scale scores. Overall, there was no evidence of improvements in healing, donor-site morbidity, postoperative pain, or functional outcomes with PRP augmentation of ACL reconstruction. This study demonstrates that, with the best available current evidence, PRP does not improve ACL reconstruction outcomes following autograft or allograft reconstruction. Gilat R, Haunschild ED, Lavoie-Gagne OZ, Tauro TM, Knapik DM, Fu MC, Cole BJ. Outcomes of the Latarjet procedure versus free bone block procedures for anterior shoulder instability: a systematic review and meta-analysis. Am J Sports Med. 2020 Aug 14. [Epub ahead of print]. Gilat et al. performed a systematic review and meta-analysis on 70 studies involving 4,540 shoulders undergoing glenoid reconstruction with either Latarjet (weighted mean follow-up of 75.8 months) or free bone block (weighted mean follow-up of 92.3 months). Both groups had improved ASES scores and the free bone block group had a significantly greater increase, but the improvements observed in other patient-reported outcome scores were not significantly different between the 2 groups. Further, no differences in the rate of recurrent instability, other complications, osteoarthritis progression, and return to sport were observed between the Latarjet and free bone block groups. Because of the heterogeneity of the studies reviewed, future high-quality studies are necessary, but this analysis supported the safety and efficacy of the Latarjet and free bone block procedures for anterior shoulder stabilization. This study demonstrates that free bone blocks (including allografts) are essentially equivalent to Latarjet for glenoid reconstruction and may be a viable option for patients with recurrent glenoid instability. Kim SH, Djaja YP, Park YB, Park JG, Ko YB, Ha CW. Intra-articular injection of culture-expanded mesenchymal stem cells without adjuvant surgery in knee osteoarthritis: a systematic review and meta-analysis. Am J Sports Med. 2020 Sep;48(11):2839-49. Epub 2019 Dec 24. This systematic review and meta-analysis included 6 RCTs with short-term follow-up between 6 and 12 months of knee osteoarthritis treatment with intra-articular, culture-expanded mesenchymal stem cells. The only significant outcome improvement after treatment was found in a cumulative pain analysis using the visual analog scale and WOMAC pain scores. However, no significant improvements were found in any of the data on cartilage repair assessed by MRI and other outcome measures. Therefore, treatment of osteoarthritis with culture-expanded mesenchymal stem cells may improve short-term pain, but it has not shown benefits regarding function or cartilage repair. This study demonstrates the potential ability of biologics, specifically mesenchymal stem cells, to improve pain in patients with knee osteoarthritis, but highlights the lack of evidence supporting a disease-modifying effect of such treatments. Kunze KN, Rossi LA, Beletsky A, Chahla J. Does the use of knotted versus knotless transosseous equivalent rotator cuff repair technique influence the incidence of retears? A systematic review. Arthroscopy. 2020 Jun;36(6):1738-46. Epub 2020 Feb 11. The authors systematically reviewed 7 studies including 552 shoulders (with patients with a weighted mean age of 60.5 years) undergoing rotator cuff repair with a weighted mean follow-up of 27.8 months. Overall, the incidence and location of retears, as evaluated through imaging and reported using ranges, were similar between patients who underwent a knotless transosseous equivalent rotator cuff repair technique and those who underwent the repair with a knotted technique. More specifically, for patients who underwent a knotless transosseous equivalent rotator cuff repair technique, type-I retears ranged from 42.9% to 100% and type-II retears ranged from 0% to 57.1%. These ranges were compared with patients who underwent a knotted transosseous equivalent rotator cuff repair technique, in whom the incidence of type-I retears ranged from 20% to 100% and the incidence of type-II retears ranged from 0% to 100%. These comparisons led to the conclusion that outcomes with regard to retears between knotless and knotted transosseous equivalent rotator cuff repair techniques are comparable. This study demonstrates that both knotted and knotless repairs allow for similar outcomes with respect to retear rates, and, thus, it is likely acceptable for surgeons to choose either technique for arthroscopic rotator cuff repair. Liu YF, Hong CK, Hsu KL, Kuan FC, Chen Y, Yeh ML, Su WR. Intravenous administration of tranexamic acid significantly improved clarity of the visual field in arthroscopic shoulder surgery. A prospective, double-blind, and randomized controlled trial. Arthroscopy. 2020 Mar;36(3):640-7. Epub 2019 Dec 20. In this placebo-controlled RCT, patients were randomized to receive 1,000 mg of either tranexamic acid or plain saline solution intravenously at 10 minutes prior to arthroscopic rotator cuff repair. Every 15 minutes throughout the procedure, visual clarity was graded on a scale of 1 to 3, with 1 indicating poor clarity and 3 indicating a clear field. A significantly greater percentage of grade-3 ratings (53.7% tranexamic acid compared with 40.5% control) and a higher mean visual score were observed in the tranexamic acid group compared with the control group. There were no complications in either group, and similarities were found between groups with regard to operative time, estimated perioperative blood loss, degree of shoulder swelling, and duration of inpatient stay. Interestingly, postoperative subjective pain scores and the use of analgesics were both significantly lower in the tranexamic acid group than the control group. The authors concluded that tranexamic acid delivered intravenously is a safe and effective way to improve visual clarity during an arthroscopic shoulder surgical procedure. This study provides clinically meaningful data supporting the use of intravenous tranexamic acid during shoulder arthroscopy, without increased complications. These data can be used to help to support the use of this product not only to reduce blood loss, but also to improve postoperative pain. Raeissadat SA, Ghorbani E, Sanei Taheri M, Soleimani R, Rayegani SM, Babaee M, Payami S. MRI changes after platelet rich plasma injection in knee osteoarthritis (randomized clinical trial). J Pain Res. 2020 Jan 10;13:65-73. Raeissadat et al. performed this double-blinded RCT study to assess objective measures with regard to the effects of PRP on cartilage in treating knee osteoarthritis. In this study, there were 23 patients (46 knees) with bilateral knee osteoarthritis grades 1 through 3, and each patient’s knees were randomized to either receive the PRP treatment or serve as a control. Outcomes were measured at baseline and at 8 months after intervention and were composed of visual analog scale and WOMAC scores as well as MRI sequences. The mean total WOMAC and visual analog scale changes were significantly higher from baseline to after treatment in the PRP group compared with the control group. Among the MRI outcomes measured, the PRP group had significant changes in patellofemoral cartilage volume and synovitis. Not only does a PRP injection improve pain and function in patients with knee osteoarthritis, but it also results in significant structural changes within the knee observed through radiographic imaging. This study shows that, in the short term, PRP may result in both subjective and objective improvements for patients with knee osteoarthritis, potentially demonstrating a disease-modifying effect. Zamborsky R, Danisovic L. Surgical techniques for knee cartilage repair: an updated large-scale systematic review and network meta-analysis of randomized controlled trials. Arthroscopy. 2020 Mar;36(3):845-58. Zamborsky and Danisovic included 21 RCTs to investigate various surgical knee cartilage repair techniques and to compare their efficacies, including microfracture, autologous chondrocyte implantation, osteochondral autograft transplantation, and matrix-induced autologous chondrocyte implantation. Microfracture had significantly poorer results compared with all 3 of the cartilage repair techniques at >3-year follow-up and also had higher failure rates than autologous chondrocyte implantation at 10 years after the surgical intervention. Further, at the 1-year follow-up, patients who underwent osteochondral autograft transplantation had greater rates of return to sport than patients who underwent microfracture, but the authors observed poorer results compared with patients who underwent matrix-induced autologous chondrocyte implantation. Also, compared with microfracture, chondrocyte implantation-classified procedures had significantly improved Knee injury and Osteoarthritis Outcome Scores. Finally, the incidences of reintervention surgical procedures and adverse events did not differ among all of the techniques. Although it is not clear which method among the cartilage repair techniques is superior, scoring and analysis showed that microfracture was consistently the least effective in treating articular knee cartilage defects. Consistent with many other studies, this study demonstrates the reduced effectiveness of microfracture compared with more advanced cartilage repair and restoration techniques.