This update reflects recently published evidence in the field of sports medicine surgery from October 2017 through January 2019. Although this review is not exhaustive of all research that might be pertinent to sports medicine, it highlights key articles that contribute to the existing evidence base in the field of the subspecialty. Included are the most impactful clinical and basic science studies, with specific emphasis on Level-I and II studies and with the focus of our search on articles published in The Journal of Bone & Joint Surgery, The American Journal of Sports Medicine, and Arthroscopy: The Journal of Arthroscopic and Related Surgery.
Anterior Cruciate Ligament (ACL)
The clinical outcomes of patients undergoing single-bundle compared with double-bundle ACL reconstruction continue to be equivalent. In a randomized controlled trial (RCT) in Norway that included 120 patients who underwent either single-bundle or double-bundle ACL reconstruction with 2 years of follow-up, no difference between the 2 techniques in any patient-reported outcomes, knee laxity measurements, or activity levels was found1. In another RCT comparing single-bundle and double-bundle ACL reconstruction, in Germany, 53 (83%) of 64 patients were available for follow-up at 5 years2. The authors found no subjective difference in patient-reported outcome, instrumented laxity, presence of a pivot shift, or complication rate between the 2 surgical methods. These results, along with those of other published comparative trials over the last 5 years, strongly suggest that the routine use of 2 bundles to primarily reconstruct a torn ACL adds no clinical benefit over a well-positioned single-bundle ACL reconstruction.
Optimizing perioperative pain control after ACL reconstruction continues to be a goal of many sports medicine surgeons. An RCT comparing femoral nerve block and periarticular injection for pain control after autograft hamstring ACL reconstruction included 129 nonblinded patients randomized into each group3. The periarticular-injection group received a solution consisting of ropivacaine, epinephrine, methylprednisolone, and morphine injected directly into the infrapatellar fat pad, the capsule above the medial and lateral menisci, the hamstring harvest site, and the subcutaneous areas around each of the portals. The femoral nerve block, performed preoperatively by an experienced anesthesiologist using ultrasound guidance, consisted of ropivacaine at a volume based on the patient’s weight. The investigators found that the periarticular-injection group had significantly lower pain scores at 4, 8, 24, and 48 hours postoperatively and that this difference reached a minimum clinically important difference. All patients were admitted to the hospital after surgery, and the study showed less overall opioid use in the periarticular-injection group. There were no differences between the groups in complication rates or in the rate of postoperative nausea and vomiting.
A 3-part series evaluated the role of femoral nerve blocks, adductor canal blocks, and local instillation analgesia in the setting of outpatient ACL reconstruction4-6. The results of the systematic reviews and meta-analyses demonstrated limited efficacy of femoral nerve blocks and adductor canal blocks at reducing postoperative pain and opioid consumption compared with placebo. Despite questions regarding the ideal composition of analgesic mixture used and the location for local instillation analgesia after ACL reconstruction, there appeared to be a measurable benefit of local instillation analgesia, with minimal complications.
Small-diameter hamstring harvest for ACL reconstruction remains a challenge for surgeons using quadrupled hamstring autograft. A systematic review and meta-analysis assessed the risk of retear following ACL reconstruction using a hybrid graft of autograft augmented with allograft tissue7. The selection bias in each of the examined studies was high, with varying cutoffs or rationales for hybridization in several of the studies. It was not demonstrated that augmentation of a soft-tissue autograft with allograft during ACL reconstruction results in clear harm or benefit.
In a long-term, randomized study performed in Norway, patient outcomes after operative knee cartilage repair using microfracture versus mosaicplasty were compared; better long-term outcomes in the mosaicplasty group at a minimum of 15 years of follow-up were reported8. Patients with 1 or 2 focal femoral lesions measuring between 2 and 6 cm2 were included. The study had only 20 patients in each arm, but the difference between the groups in the Lysholm score was both clinically important and statistically significant. The investigators were able to achieve 100% inclusion at the time of final follow-up and found that more patients in the mosaicplasty group reported they would have the surgery again knowing their final outcome. The authors did not specify lesion size for each patient, which could have biased the results in favor of mosaicplasty given the now-accepted understanding that microfracture results are less durable in patients with lesions of >2 cm2.
A systematic review and meta-analysis evaluating varying graft options for isolated medial patellofemoral ligament (MPFL) reconstruction demonstrated no difference among autograft, allograft, or synthetic grafts with respect to recurrent instability, postoperative complications, or objective patient-reported outcomes9. Some weaknesses of this analysis, which may limit what can be inferred, were that the average follow-up time period within the included studies was not reported and there was notable variability in the reporting of utilized grafts. Gracilis and semitendinosus autografts were by far the most commonly reported grafts among the 45 studies, while allograft (tibialis anterior and unspecified) was used in only 2 of the studies and synthetic grafts (suture) were used in only 3 studies. The finding of no difference in results may suggest that surgeon preference, comfort, and clinical judgment should continue to dictate graft selection when treating patellar instability with isolated MPFL reconstruction. Additional studies evaluating the use of allograft and suture-based synthetic grafts are needed to more fully assess the impact that graft choice has on long-term outcomes.
In an RCT performed in Sweden investigating acute repair within 2 weeks of injury for first-time traumatic lateral dislocation of the patella in skeletally immature patients, treatment with suture anchors was compared with nonoperative management10. The authors found a significantly lower rate of recurrent dislocation in the operative group (22% versus 43%) but no difference between the groups was demonstrated with respect to objective or subjective measures of knee function at 2 years of follow-up. The study may have been underpowered to detect a difference in outcomes other than the redislocation rate between the groups, but there was an association with poorer outcomes for patients who experienced redislocation compared with those who did not, regardless of treatment. The role of reconstruction (as opposed to direct repair) or other types of repair techniques (other than using suture anchors) in this patient population is still unclear.
In a large RCT performed in the United Kingdom, patients with ≥3 months of subacromial pain with an intact rotator cuff who had already completed a nonoperative program of physical therapy and injection were randomized to 1 of 3 groups: arthroscopic subacromial decompression, diagnostic arthroscopy (“sham” surgery), or no intervention11. Of 740 eligible patients, 313 were randomized. The per-protocol rate of follow-up at 1 year was 64%, as there was a fair amount of noncompliance with treatment allocation for a variety of reasons; the overall rate of follow-up (intention-to-treat) was 85%. At 6 months and 1 year, patient-reported outcome scores were significantly better in both surgical groups compared with no treatment, but there was no clinically important difference. All groups demonstrated statistically significant and clinically important improvement within the study period. These data suggest that patients with subacromial impingement without a full-thickness rotator cuff tear improve with time, regardless of management. The results also suggest that surgical decompression may offer a slight benefit over nonoperative management because of the placebo effect, as the outcomes of decompression were equivalent to those of sham surgery. In assessing the methodology of any study performing sham surgery, however, the benefit of simply irrigating a symptomatic joint (as was performed in this sham-surgery cohort) is not entirely clear. The authors of future randomized trials utilizing sham surgery might consider performing skin incisions only to truly assess the placebo effect of arthroscopic surgery.
Investigators at the Rothman Institute performed an RCT investigating the effect of a formal preoperative education program that detailed recommended postoperative narcotic use, side effects, dependence, and the addiction potential of patient opioid use after arthroscopic rotator cuff repair surgery12. A total of 134 patients were enrolled, and randomization was performed with a computer-generated scheme. The patients in the education group watched a short (2-minute) narrated video and received a handout discussing the risks of narcotic overuse/abuse. All patients were blinded to the purpose of the study at the time of education. The study group was found to have consumed significantly less narcotic medication at 6 weeks (33% less) and 12 weeks (42% less) compared with the control group. Patients who were opioid users prior to surgery (28% of the study population) and who were randomized to the preoperative education group were 6.8 times more likely to discontinue narcotic use, suggesting that a preoperative education program may especially benefit those at highest risk of postoperative narcotic use.
Clavicle and Acromioclavicular (AC) Joint
Unstable AC joint injuries are uncommon and can be challenging to manage when surgery is indicated. A systematic review and meta-analysis of treatment of high-grade AC dislocations found no difference between operative and nonoperative management with respect to functional outcome scores13. The factors limiting interpretation of this study’s findings include the grouping together of type-III, IV, and V injuries; the high variability found between the studies; and the relative lack of studies using contemporary surgical techniques, such as soft-tissue or synthetic grafts or suspension fixation devices. In 14 of the 20 studies, coracoid screws, hook plates, or Kirschner wires were used for primary fixation. Additional research is needed to evaluate the outcomes and cost-effectiveness of surgery for high-grade AC joint injuries using contemporary techniques and implants.
Recent large, well-designed randomized trials comparing surgical and nonsurgical management of displaced midshaft clavicular fractures have consistently demonstrated reduced risk of nonunion with surgical management at the cost of postoperative complications. A recent meta-analysis again demonstrated these findings as well as an increased risk of requiring surgery for nonunion after nonoperative treatment, but it did not demonstrate a clear difference in functional outcomes and pain scores past 1 year14. Surgical treatment may be a better option for patients who need earlier return of function, who desire to minimize the risk of nonunion, and who find the associated surgical risk of infection and the potential for implant removal to be acceptable.
Biceps and Labrum
The surgical management of symptomatic superior labral tears has evolved over the past 2 decades, trending away from superior labral anterior-to-posterior (SLAP) tear repair and toward biceps tenodesis. A systematic review and meta-analysis comparing SLAP repair and biceps tenodesis for SLAP tears found better patient satisfaction and return to sport after biceps tenodesis15. Continued evaluation to determine the optimal indications for surgical management of SLAP tears and the best surgical approach is still needed. However, it appears that the decreasing performance of SLAP repair surgery corresponds with, and is justified by, recent outcome studies16,17.
Surgical outcomes after hip arthroscopy have been published at an increasing rate over the last decade. Minkara et al. recently performed a comprehensive systematic review and meta-analysis of all primary studies of hip arthroscopy published in the English language since the first preliminary report of arthroscopic treatment for femoroacetabular impingement (FAI) in 200518. Studies with <6 months of follow-up, review articles, case reports, and technique articles were excluded. Thirty-one articles (mostly case series), including a total of almost 2,000 patients, met the criteria. A tremendous amount of information was presented in the review, but a few specific notable outcomes were observed. The pooled rate of reoperation was 5.5%, with total hip arthroplasty representing 77% of reoperation procedures and revision hip arthroscopy, 13%. Almost one-fifth of the reoperations came from a single study that evaluated hip arthroscopy in patients >50 years of age. Across the studies, the risk of clinically notable complications was 1.7%, with heterotopic ossification and transient neurapraxia being the most common. The rate of return to sport was 88%. The mean alpha angle improved from 72° to 49°. All patient-reported hip outcome scores improved postoperatively, with the highest average increase in the Hip Outcome Score sports scale (increase of 42 points). Predictors of positive and negative outcomes were summarized from the cited articles, with several studies citing advanced age, substantial joint-space narrowing, or elevated Tönnis grade as risk factors for a poor outcome or conversion to arthroplasty.
While a number of prospective and retrospective studies have shown the efficacy of arthroscopic surgery for FAI, there are very few well-designed clinical trials that have directly compared surgery and nonoperative care for this condition. A critically important, assessor-blinded RCT comparing hip arthroscopy and nonoperative management for the treatment of FAI was performed in the United Kingdom19. The authors aimed to measure the clinical effectiveness of hip arthroscopy compared with “best conservative care” for FAI via the International Hip Outcome Tool (iHOT)-33 at 1 year post-randomization. Health-related quality-of-life measures were also assessed, as were adverse events and health-care resource use. A total of 348 patients were enrolled; the follow-up rate at 1 year was 92%. Patients were an average age of 35 years, with a predominance of men. There was only 8% crossover from conservative care to the surgical group. The mean adjusted difference in iHOT-33 scores at 1 year was 6.8, in favor of hip arthroscopy and surpassing the minimal clinically important difference of 6.1. In a per-protocol analysis, this number increased to 8.2, in favor of hip arthroscopy. As expected, adverse events were more frequent in the arthroscopy cohort, with 1 serious surgical complication (deep infection). A within-trial economic evaluation suggested that hip arthroscopy was not cost-effective during the 1-year trial period compared with conservative care, but further follow-up is planned, including 2, 3, 5, and 10-year economic analyses to better assess longer-term cost-effectiveness of both operative and nonoperative treatments.
In a well-designed prospective randomized trial in Denmark that included 75 patients who underwent surgical repair of an Achilles tendon rupture, no differences in tendon elongation, cross-sectional area on magnetic resonance imaging (MRI), or patient-reported outcomes were demonstrated between patients who were prescribed late weight-bearing (full weight-bearing at 9 weeks) versus early weight-bearing (5 weeks) following surgery20. Functional deficits were noted in all groups out to 1 year postoperatively, however. Early functional rehabilitation continues to appear to be a safe method of recovering after Achilles tendon repair, but patients should be counseled appropriately regarding the potential length of overall recovery time.
There continues to be great enthusiasm driven by clinicians, patients, and industry surrounding the potential benefits and utility of biologics in sports medicine. However, many well-designed studies continue to show conflicting results after the use of platelet-rich plasma (PRP). One recent RCT that assessed the effect of PRP on anterior knee pain after patellar tendon harvest for ACL reconstruction found no difference in bone-healing or pain scores with the addition of PRP to the patellar harvest site21. Almost one-third of all of the patients continued to have kneeling pain at 2 years following surgery. A meta-analysis of 4 RCTs comparing PRP injection with saline solution placebo injection for Achilles tendinopathy, with a pooled cohort of 170 patients, demonstrated no difference in any patient-reported outcome or objective measurement of tendon thickness or neovascularity as measured by ultrasound and color Doppler activity, respectively22.
Biologic scaffolds represent an alternate vehicle for possibly improving tendon-healing biology. In a recent study, 112 patients aged 50 to 85 years with medium-to-large rotator cuff tears were randomized to 1 of 2 operative groups: rotator cuff repair with use of a standard suture-bridge technique or cuff repair using the same suture-bridge technique augmented with a 3-dimensional (3D) type-I collagen scaffold23. The rate of follow-up was 93% at 2 years, at which time all patients were assessed with use of patient-reported outcome measures and MRI and, for 3 patients each in the study and control groups, biopsy evaluation. The 2 groups had similar preoperative characteristics, but the most important finding in this study was that the retear rate based on MRI at the time of final follow-up was 34% in the control group compared with 13.7% in the collagen scaffold-augmented group (p = 0.02). Histologically, among the 6 samples, there were more aligned fibers and larger fiber diameters in the study group compared with the control group (p < 0.05). The authors found no difference in Constant and UCLA (University of California, Los Angeles) scores at the time of final follow-up, but results favored the collagen group at 6 months and 1 year. While the reduction in the retear rate is a promising finding for those supporting the use of biologics during shoulder surgery, more research is needed to understand why differences in patient-reported outcomes often cannot be documented for patients who experience a retear of the rotator cuff and those who do not.
The editorial staff of The Journal reviewed a large number of recently published research studies related to the musculoskeletal system that received a higher Level of Evidence grade. In addition to articles cited already in the Update, 8 other articles with a higher Level of Evidence grade were identified that were relevant to sports medicine. A list of those titles is appended to this review after the standard bibliography. We have provided a brief commentary about each of the articles to help guide your further reading, in an evidence-based fashion, in this subspecialty area.
Upcoming Meetings and Events Related to Sports Medicine
- Asia-Pacific Knee, Arthroscopy and Sports Medicine Society (APKASS) Summit: April 18-21, 2019, in Chengdu, China (http://2019summit.medmeeting.org/7632?lang=en).
- International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine (ISAKOS) Congress: May 12-16, 2019, in Cancun, Mexico (https://www.isakos.com/2019Congress).
- Arthroscopy Association of North America (AANA) Annual Meeting: May 2-4, 2019, in Orlando, Florida (http://www.aana.org).
- American Orthopaedic Society for Sports Medicine (AOSSM) Annual Meeting: July 11-14, 2019, in Boston, Massachusetts (http://www.sportsmed.org).
Aliste J, Bravo D, Fernández D, Layera S, Finlayson RJ, Tran DQ. A randomized comparison between interscalene and small-volume supraclavicular blocks for arthroscopic shoulder surgery. Reg Anesth Pain Med. 2018 Aug;43(6):590-5.
The authors compared the use of interscalene brachial plexus block (ISB) with a specific technique of small-volume supraclavicular brachial plexus block (SCB), in an effort to reduce the risk of hemidiaphragmatic paralysis. There were no differences between the groups in demographics, type of surgery (rotator cuff repair, acromioplasty, Bankart repair), or surgical duration. The investigators found that ISB resulted in a much higher rate of hemidiaphragmatic paralysis at 30 minutes after block administration (95% compared with 9%; p < 0.001). However, the block onset time was also shorter for ISB (10 versus 24 minutes; p < 0.001). Postoperative pain scores were equivalent at all time points, including the primary outcome of pain at 30 minutes postoperatively. The study thus suggests that the technique of small-volume SCB could be equally effective as, and safer than, ISB for patients undergoing arthroscopic shoulder surgery.
Belk JW, Kraeutler MJ, Carver TJ, McCarty EC. Knee osteoarthritis after anterior cruciate ligament reconstruction with bone-patellar tendon-bone versus hamstring tendon autograft: a systematic review of randomized controlled trials. Arthroscopy. 2018 Apr;34(4):1358-65. Epub 2018 Feb 1.
This systematic review of Level-I and II studies (6 Level-I and 2 Level-II) compared patellar tendon with hamstring autograft for ACL reconstruction. By pooling data, the authors identified 237 patients in the patellar tendon group and 268 in the hamstring group, with a mean follow-up time of 11.5 years. As is often the case, there was variability in the surgical technique used in each study as well as variability of the reported outcomes data. The main finding was that there were no significant differences between autograft types in terms of knee osteoarthritis, as determined by final radiographic scores (either Kellgren-Lawrence classification or Ahlbäck and Fairbank rating system). Of all of the patients in the study for whom radiographic data were collected, 51.5% had a Kellgren-Lawrence grade of II (definite osteophytes and possible joint-space narrowing on standing radiographs) or greater at the time of final follow-up.
Brown AJ, Shimozono Y, Hurley ET, Kennedy JG. Arthroscopic repair of lateral ankle ligament for chronic lateral ankle instability: a systematic review. Arthroscopy. 2018 Aug;34(8):2497-503. Epub 2018 May 2.
Despite short follow-up duration and the overall poor or fair quality of available comparative studies, a recent systematic review found no difference in outcomes or complications between open and arthroscopic repair for chronic lateral ankle instability, suggesting that surgeon preference should primarily determine the surgical technique that is performed. The least expensive surgical method should be considered to treat this condition if the most cost-effective outcome is desired.
Chahla J, Moatshe G, Cinque ME, Dornan GJ, Mitchell JJ, Ridley TJ, LaPrade RF. Single-bundle and double-bundle posterior cruciate ligament reconstructions: a systematic review and meta-analysis of 441 patients at a minimum 2 years’ follow-up. Arthroscopy. 2017 Nov;33(11):2066-80. Epub 2017 Aug 31.
This recent systematic review and meta-analysis demonstrated improved outcomes after posterior cruciate ligament (PCL) reconstruction when either a single-bundle or double-bundle reconstruction technique was used. There was a significant improvement in the International Knee Documentation Committee score and objective measures of posterior tibial stability after double-bundle reconstruction compared with single-bundle reconstruction. The main confounder that questions the validity of the findings was the consistently larger total diameter of graft utilized for double-bundle reconstructions in all but 1 of the analyzed studies. In the single study utilizing comparable total diameters of graft for both single-bundle and double-bundle reconstructions, no objective differences were found. Additional study is warranted to determine if increased graft diameter, rather than using a double-bundle technique, improves outcomes after PCL reconstruction.
Mellor R, Bennell K, Grimaldi A, Nicolson P, Kasza J, Hodges P, Wajswelner H, Vicenzino B. Education plus exercise versus corticosteroid injection use versus a wait and see approach on global outcome and pain from gluteal tendinopathy: prospective, single blinded, randomised clinical trial. BMJ. 2018 May 2;361:k1662.
This single-blinded RCT compared 8 weeks of physiotherapy-led education and exercise (PT), the use of a single corticosteroid injection, and a wait-and-see approach in the treatment of patients with greater trochanteric pain syndrome. A total of 204 patients were enrolled, with 93% follow-up at 1 year. After 8 weeks, the global rating of change (percent success) was 77% for the PT group, 58% for the corticosteroid group, and 30% for the wait-and-see group. The PT group remained at 79% success at 1 year, while there were no differences between the injection and wait-and-see groups at 1 year (58% and 52% success, respectively). To our knowledge, this is the only RCT to specifically assess the effect of PT on greater trochanteric pain syndrome and supports the use of education and therapeutic exercise as the primary intervention for this condition.
Moatshe G, Kruckeberg BM, Chahla J, Godin JA, Cinque ME, Provencher MT, LaPrade RF. Acromioclavicular and coracoclavicular ligament reconstruction for acromioclavicular joint instability: a systematic review of clinical and radiographic outcomes. Arthroscopy. 2018 Jun;34(6):1979-1995.e8. Epub 2018 Mar 21.
The preferred surgical management of high-grade AC joint injuries continues to be unclear. This recent review demonstrated good postoperative patient-reported outcomes after a number of different reconstruction techniques, with relatively low unplanned reoperation rates. Techniques using hook plates or Kirschner wires were found to be associated with the highest complication rates.
Steelman VM, Chae S, Duff J, Anderson MJ, Zaidi A. Warming of irrigation fluids for prevention of perioperative hypothermia during arthroscopy: a systematic review and meta-analysis. Arthroscopy. 2018 Mar;34(3):930-942.e2. Epub 2017 Dec 6.
This systematic review and meta-analysis of 6 Level-I and II studies compared the effect of warmed irrigation fluids (32° to 40°C) and room-temperature fluids (20° to 22°C) on perioperative hypothermia (<36°C) among patients undergoing shoulder, hip, or knee arthroscopy. Pooled analysis found that the warming of irrigation fluids did significantly decrease the risk of hypothermia (odds ratio [OR], 0.15; p = 0.0001), decreased the risk of shivering (OR, 0.25; p = 0.03), increased the lowest mean temperature (mean difference of 0.46°C; p = 0.01), and decreased the maximum temperature drop (mean difference of −0.64°C; p < 0.0001). These results suggest that the simple intervention of warming arthroscopy fluid can help maintain normothermia perioperatively and decrease the risk of shivering.
Zhu J, Jiang H, Marshall B, Li J, Tang X. Low-molecular-weight heparin for the prevention of venous thromboembolism in patients undergoing knee arthroscopic surgery and anterior cruciate ligament reconstruction: a meta-analysis of randomized controlled trials. Am J Sports Med. 2018 Aug 16:363546518782705. [Epub ahead of print].
A meta-analysis performed in China of RCTs evaluating the use of low-molecular-weight heparin (LMWH) demonstrated little effect on deep-vein thrombosis (DVT) but an increase in bleeding events after simple knee arthroscopy, whereas some reduction in DVT with no increase in bleeding events after ACL reconstruction was found. The routine use of low-molecular-weight heparin for DVT prophylaxis after simple knee arthroscopy in patients without risk factors is likely not efficacious. The risk-benefit ratio of routine DVT prophylaxis with low-molecular-weight heparin after ACL surgery is still unclear.
1. Aga C, Risberg MA, Fagerland MW, Johansen S, Trøan I, Heir S, Engebretsen L. No difference in the KOOS Quality of Life Subscore between anatomic double-bundle and anatomic single-bundle anterior cruciate ligament reconstruction of the knee: a prospective randomized controlled trial with 2 years’ follow-up. Am J Sports Med. 2018 Aug;46(10):2341-54. Epub 2018 Jul 18.
2. Mayr HO, Bruder S, Hube R, Bernstein A, Suedkamp NP, Stoehr A. Single-bundle versus double-bundle anterior cruciate ligament reconstruction-5-year results. Arthroscopy. 2018 Sep;34(9):2647-53. Epub 2018 Jun 21.
3. Kurosaka K, Tsukada S, Nakayama H, Iseki T, Kanto R, Sugama R, Yoshiya S. Periarticular injection versus femoral nerve block for pain relief after anterior cruciate ligament reconstruction: a randomized controlled trial. Arthroscopy. 2018 Jan;34(1):182-8. Epub 2017 Dec 6.
4. Vorobeichik L, Brull R, Joshi GP, Abdallah FW. Evidence basis for regional anesthesia in ambulatory anterior cruciate ligament reconstruction: part I-femoral nerve block. Anesth Analg. 2019 Jan;128(1):58-65.
5. Sehmbi H, Brull R, Shah UJ, El-Boghdadly K, Nguyen D, Joshi GP, Abdallah FW. Evidence basis for regional anesthesia in ambulatory arthroscopic knee surgery and anterior cruciate ligament reconstruction: part II: adductor canal nerve block-a systematic review and meta-analysis. Anesth Analg. 2019 Feb;128(2):223-38.
6. Yung EM, Brull R, Albrecht E, Joshi GP, Abdallah FW. Evidence basis for regional anesthesia in ambulatory anterior cruciate ligament reconstruction: part III: local instillation analgesia-a systematic review and meta-analysis. Anesth Analg. 2017 Nov 30. [Epub ahead of print].
7. Abouljoud MM, Everhart JS, Sigman BO, Flanigan DC, Magnussen RA. Risk of retear following anterior cruciate ligament reconstruction using a hybrid graft of autograft augmented with allograft tissue: a systematic review and meta-analysis. Arthroscopy. 2018 Oct;34(10):2927-35. Epub 2018 Sep 6.
8. Solheim E, Hegna J, Strand T, Harlem T, Inderhaug E. Randomized study of long-term (15-17 years) outcome after microfracture versus mosaicplasty in knee articular cartilage defects. Am J Sports Med. 2018 Mar;46(4):826-31. Epub 2017 Dec 18.
9. McNeilan RJ, Everhart JS, Mescher PK, Abouljoud M, Magnussen RA, Flanigan DC. Graft choice in isolated medial patellofemoral ligament reconstruction: a systematic review with meta-analysis of rates of recurrent instability and patient-reported outcomes for autograft, allograft, and synthetic options. Arthroscopy. 2018 Apr;34(4):1340-54. Epub 2018 Feb 1.
10. Askenberger M, Bengtsson Moström E, Ekström W, Arendt EA, Hellsten A, Mikkelsen C, Janarv PM. Operative repair of medial patellofemoral ligament injury versus knee brace in children with an acute first-time traumatic patellar dislocation: a randomized controlled trial. Am J Sports Med. 2018 Aug;46(10):2328-40. Epub 2018 May 30.
11. Beard DJ, Rees JL, Cook JA, Rombach I, Cooper C, Merritt N, Shirkey BA, Donovan JL, Gwilym S, Savulescu J, Moser J, Gray A, Jepson M, Tracey I, Judge A, Wartolowska K, Carr AJ; CSAW Study Group. Arthroscopic subacromial decompression for subacromial shoulder pain (CSAW): a multicentre, pragmatic, parallel group, placebo-controlled, three-group, randomised surgical trial. Lancet. 2018 Jan 27;391(10118):329-38. Epub 2017 Nov 20.
12. Syed UAM, Aleem AW, Wowkanech C, Weekes D, Freedman M, Tjoumakaris F, Abboud JA, Austin LS. Neer Award 2018: the effect of preoperative education on opioid consumption in patients undergoing arthroscopic rotator cuff repair: a prospective, randomized clinical trial. J Shoulder Elbow Surg. 2018 Jun;27(6):962-7. Epub 2018 Mar 26.
13. Chang N, Furey A, Kurdin A. Operative versus nonoperative management of acute high-grade acromioclavicular dislocations: a systematic review and meta-analysis. J Orthop Trauma. 2018 Jan;32(1):1-9.
14. Ahmed AF, Salameh M, AlKhatib N, Elmhiregh A, Ahmed GO. Open reduction and internal fixation versus nonsurgical treatment in displaced midshaft clavicle fractures: a meta-analysis. J Orthop Trauma. 2018 Jul;32(7):e276-83.
15. Hurley ET, Fat DL, Duigenan CM, Miller JC, Mullett H, Moran CJ. Biceps tenodesis versus labral repair for superior labrum anterior-to-posterior tears: a systematic review and meta-analysis. J Shoulder Elbow Surg. 2018 Oct;27(10):1913-9. Epub 2018 May 24.
16. Erickson J, Lavery K, Monica J, Gatt C, Dhawan A. Surgical treatment of symptomatic superior labrum anterior-posterior tears in patients older than 40 years: a systematic review. Am J Sports Med. 2015 May;43(5):1274-82. Epub 2014 Jun 24.
17. Gottschalk MB, Karas SG, Ghattas TN, Burdette R. Subpectoral biceps tenodesis for the treatment of type II and IV superior labral anterior and posterior lesions. Am J Sports Med. 2014 Sep;42(9):2128-35. Epub 2014 Jul 22.
18. Minkara AA, Westermann RW, Rosneck J, Lynch TS. Systematic review and meta-analysis of outcomes after hip arthroscopy in femoroacetabular impingement. Am J Sports Med. 2018 Jan 1:363546517749475. [Epub ahead of print].
19. Griffin DR, Dickenson EJ, Wall PDH, Achana F, Donovan JL, Griffin J, Hobson R, Hutchinson CE, Jepson M, Parsons NR, Petrou S, Realpe A, Smith J, Foster NE; FASHIoN Study Group. Hip arthroscopy versus best conservative care for the treatment of femoroacetabular impingement syndrome (UK FASHIoN): a multicentre randomised controlled trial. Lancet. 2018 Jun 2;391(10136):2225-35. Epub 2018 Jun 1.
20. Eliasson P, Agergaard AS, Couppé C, Svensson R, Hoeffner R, Warming S, Warming N, Holm C, Jensen MH, Krogsgaard M, Kjaer M, Magnusson SP. The ruptured Achilles tendon elongates for 6 months after surgical repair regardless of early or late weightbearing in combination with ankle mobilization: a randomized clinical trial. Am J Sports Med. 2018 Aug;46(10):2492-502. Epub 2018 Jul 2.
21. Walters BL, Porter DA, Hobart SJ, Bedford BB, Hogan DE, McHugh MM, Klein DA, Harousseau K, Nicholas SJ. Effect of intraoperative platelet-rich plasma treatment on postoperative donor site knee pain in patellar tendon autograft anterior cruciate ligament reconstruction: a double-blind randomized controlled trial. Am J Sports Med. 2018 Jul;46(8):1827-35. Epub 2018 May 9.
22. Zhang YJ, Xu SZ, Gu PC, Du JY, Cai YZ, Zhang C, Lin XJ. Is platelet-rich plasma injection effective for chronic Achilles tendinopathy? A meta-analysis. Clin Orthop Relat Res. 2018 Aug;476(8):1633-41.
23. Cai YZ, Zhang C, Jin RL, Shen T, Gu PC, Lin XJ, Chen JD. Arthroscopic rotator cuff repair with graft augmentation of 3-dimensional biological collagen for moderate to large tears: a randomized controlled study. Am J Sports Med. 2018 May;46(6):1424-31. Epub 2018 Mar 13.