Editorial Commentary: Low-Grade Infections May Contribute to Anterior Cruciate Ligament Reconstruction Graft Failure.

The etiology of anterior cruciate ligament (ACL) reconstruction failure is often multifactorial, and the role of subclinical bacterial colonization in ACL reconstruction failure has not been fully elucidated. Although the presence of bacterial metabolism in and of itself does not indicate true clinical infection, low-grade infections may contribute to ACL reconstruction graft failure. Bacterial biofilms on soft tissue grafts are shown to change the crimp patterns of collagen and lower graft load to failure. In addition, bacterial DNA has been reported in 80-87% of failed ACL grafts during revision surgery compared to only 20% of primary ACL grafts. Also, higher bacterial DNA concentration is associated with tibial tunnel widening. Further study is needed to establish if any causal relationship between bacterial colonization and ACL graft failure exists. But it does seem that the circumstantial evidence is pointing to such a relationship.

Elevated Posterior Tibial Slope Is Associated With Anterior Cruciate Ligament Reconstruction Failures: A Systematic Review and Meta-analysis.

PURPOSE: To evaluate the association of posterior tibial slope (PTS) with anterior cruciate ligament (ACL) reinjury following primary ACL reconstruction. METHODS: PubMed, Scopus, Embase, and CINAHL databases were searched from inception through March 1, 2021, to retrieve relevant studies. Comparative studies reporting PTS measurements in a cohort of patients experiencing ACL graft failure versus patients with intact primary ACL reconstruction or studies comparing patients undergoing revision ACL reconstruction versus primary ACL reconstruction were included for analysis. A random-effects model was used to calculate the overall standardized mean difference (SMD) between groups. The following inclusion criteria were used: English language; full text available; Level I, II, or III evidence; studies in humans; and skeletally mature patients. RESULTS: After we systematically screened 1,912 studies, 15 studies met the inclusion/exclusion criteria. Radiographic measurements were used in 6 studies reporting medial PTS in 411 ACL failures versus 2808 controls. Patients with ACL failure had significantly greater medial PTS compared with controls (SMD 0.50; 95% confidence interval [CI] 0.23-0.77; P < .001). Magnetic resonance imaging (MRI) was used in 9 studies reporting lateral PTS measurements in 641 patients with a failed ACL reconstruction compared with 705 controls. Seven of the MRI studies also measured medial PTS in 552 failures versus 641 controls. Patients with ACL failure had significantly greater lateral PTS on MRI (SMD 0.58; 95% CI 0.13-1.03; P = .012) and medial PTS on MRI (SMD 0.59; 95% CI 0.23-0.96; P = .001) compared with controls. CONCLUSIONS: The present meta-analysis demonstrated that patients with elevated PTS on radiographs and MRI are at increased risk for ACL graft failure after primary ACL reconstruction. LEVEL OF EVIDENCE: Level III, meta-analysis of Level III studies.

Athletes and Nonathletes Show No Difference in Symptoms or Function Prior to Knee Surgery, but Those With Chronic Symptoms Show Increased Pain Catastrophizing and Kinesiophobia.

PURPOSE: To determine whether preoperative psychological status before outpatient knee surgery is influenced by athletic status, symptom chronicity, or prior surgical history. METHODS: International Knee Documentation Committee subjective scores (IKDC-S), Tegner Activity Scale scores, and Marx Activity Rating Scale scores were collected. Psychological and pain surveys included the McGill pain scale, Pain Catastrophizing Scale, Tampa Scale for Kinesiophobia 11, Patient Health Questionnaire 9, Perceived Stress Scale, New General Self-Efficacy Scale, and Life Orientation Test-Revised for optimism. Linear regression was used to determine the effects of athlete status, symptom chronicity (>6 months or ≤6 months), and history of prior surgery on preoperative knee function, pain, and psychological status after matching for age, sex, and surgical procedure. RESULTS: In total, 497 knee surgery patients (247 athletes, 250 nonathletes) completed a preoperative electronic survey. All patients were age 14 years and older and had knee pathology requiring surgical treatment. Athletes were younger than nonathletes on average (mean [SD], 27.7 [11.4] vs 41.6 [13.5] years; P < .001). The most frequently reported level of play among athletes was intramural or recreational (n = 110, 44.5%). Athletes had higher preoperative IKDC-S scores (mean [SE], 2.5 [1.0] points higher; P = .015) and lower McGill pain scores compared to nonathletes (mean [SE] 2.0 [0.85] points lower; P = .017). After matching for age, sex, athlete status, prior surgery, and procedure type, having chronic symptoms resulted in higher preoperative IKDC-S (P < .001), pain catastrophizing (P < .001), and kinesiophobia scores (P = .044). CONCLUSIONS: Athletes demonstrate no difference in symptom/pain and function scores preoperatively when compared to nonathletes of similar age, sex, and knee pathology, as well as no difference in multiple psychological distress outcomes measures. Patients with chronic symptoms have more pain catastrophizing and kinesiophobia, while those who have had prior knee surgeries have slightly higher preoperative McGill pain score. LEVEL OF EVIDENCE: Level III, cross-sectional analysis of prospective cohort study data.

An implantable shock absorber yields an 85% survival-from-arthroplasty rate through 5 years in working-age patients with medial compartment knee osteoarthritis.

PURPOSE: To evaluate the 5-year rate of survival without undergoing arthroplasty or high tibial osteotomy (HTO) in subjects with mild-to-moderate medial compartment knee osteoarthritis (OA) who were treated with an implantable shock absorber (ISA) system. METHODS: Three prospective, sequential, multicenter, international, single-arm clinical trials were conducted comprising subjects who received an ISA for symptomatic medial knee OA after failing ≥ 6 months of conservative therapy. Study outcomes were analyzed cumulatively and by enrollment group when all subjects' follow-up data exceeded the 2-year threshold after ISA implantation. Primary outcome was survival rate without conversion to arthroplasty/HTO. Secondary outcomes were changes in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function scores after ISA implantation. RESULTS: All 171 enrolled subjects (age 51 ± 9 years, body-mass index 28.5 ± 3.5 kg/m2, 38% female; study knee Kellgren-Lawrence score 2.7 ± 0.9 points) were followed for a minimum of 2, and up to 5, years after device implantation. Overall, 90.6% (155/171) of subjects survived without requiring arthroplasty/HTO at last follow-up (mean 3.2 ± 1.6 years). The Kaplan-Meyer median 3- and 5-year survival-without-arthroplasty point estimates were 89.8% (95% CI 86.5‒95.7%) and 84.9% (95% CI 75.1‒91.1%), respectively. The median 3-year estimated survival rate for the most recent study (n = 81) was 97.3%. The mean WOMAC Pain score decreased 71% from baseline to last follow-up after ISA implantation, from 58 ± 13 to 16 ± 17 points (p < 0.0001). The Function score improved 69%, decreasing from 56 ± 18 to 17 ± 17 points (p < 0.0001). CONCLUSIONS: In younger patients with mild-to-moderate symptomatic medial compartment knee OA, implantation of the ISA device resulted in a 5-year survival rate of 85% from undergoing arthroplasty or HTO. The ISA system may be an effective treatment option for working-age patients with medial knee OA who are not candidates for or do not desire more invasive surgical approaches. LEVEL OF EVIDENCE: II.

Patellofemoral articular cartilage damage is associated with poorer patient-reported outcomes following isolated medial patellofemoral ligament reconstruction.

PURPOSE: The purpose of this study was to investigate the impact of articular cartilage damage on outcomes following medial patellofemoral ligament (MPFL) reconstruction. METHODS: Record review identified 160 patients who underwent isolated MPFL reconstruction at a single institution between 2008 and 2016. Patient demographics, patellofemoral articular cartilage status at surgery, and patient anatomical measures from imaging were obtained via chart review. Patients were contacted and outcomes assessed through collection of Norwich Patellar Instability (NPI) score, Knee injury and Osteoarthritis Outcome Score (KOOS), and Marx activity score as well as an assessment for recurrent patellar dislocation. Outcomes of patients with grade 0-II patellofemoral cartilage damage were compared to those of patients with grade III-IV cartilage damage. RESULTS: One hundred twenty-two patients (76%) with a minimum of one year follow-up were contacted at a mean of 4.8 years post-operatively. A total of 63 patients (52%) had grade III or IV patellofemoral chondral damage at the time of surgery. The majority of the defects was on the medial patella (46 patients-72%) and the mean patellar defect size was 2.8 cm2. Among 93 patients who completed patient-reported outcome scores, the 52 with grade III or IV chondral damage reported a significantly poorer KOOS Quality of Life than the 44 patients with grade 0 to II chondral damage (p = 0.041), controlling for patient age, sex, BMI, and anatomical factors. CONCLUSION: Patients with grade III or IV articular cartilage damage of the patellofemoral joint at the time of MPFL reconstruction demonstrated poorer KOOS knee-related quality of life than patients without grade III or IV articular cartilage damage at a mean of 4.8 years following isolated MPFL reconstruction. LEVEL OF EVIDENCE: Level II.

Editorial Commentary: No Clear Winner When Comparing Cost-Effectiveness of Particulated Juvenile Articular Cartilage With Matrix-Induced Autologous Chondrocyte Implantation: Too Many Assumptions.

Various treatment options exist for patellar chondral lesions, including nonoperative management, marrow stimulation, cell-based strategies, and osteochondral transplantation, yet there is insufficient evidence to recommend one treatment over another. One frequently discussed downside of cell-based strategies, including particulated juvenile allograft cartilage and matrix-induced autologous chondrocyte implantation, is the associated cost. Markov modeling is a tool used for economic modeling of different treatments and may be a viable option to compare cell-based strategies for patellar chondral defects. Too many assumptions carry great risk of drawing a strong conclusion. Further high-quality studies and comparative outcome studies are needed before any definitive cost-effectiveness conclusion is made.

Smaller Iatrogenic Defects Created by Inside-Out Compared With All-Inside Meniscus Repair Devices in Human Cadaveric Model.

PURPOSE: (1) To investigate the pattern and diameter of the iatrogenic defect that meniscal repair devices impose on meniscal tissue and (2) to determine whether repair-induced defect patterns or diameters differ across devices. METHODS: Sixty-one fresh frozen human cadaveric menisci were used (n = 9; eliminated). All-inside devices (n = 9) included ULTRA FAST-FIX, FAST-FIX 360, Depuy Mitek 0° and 12° TRUESPAN, ConMed Sequent, Zimmer Biomet JuggerStitch, Stryker IvyAIR, Arthrex FiberStitch and Meniscal Cinch II. Inside-out needles (n = 4) included ConMed HiFi, Depuy Mitek ORTHOCORD, Arthrex-2-0 FiberWire, and Stryker SharpShooter. Following India Ink staining, implant devices were inserted into cadaveric menisci. Samples were fixed in formalin solution and imaged with a high-resolution camera. Defects were classified by qualitative evaluation. Defect and needle diameter were quantified with software assistance. Statistical analysis was performed using analysis of variance testing. RESULTS: We analyzed 644 iatrogenic defects with mean defect diameter of 1.96 mm (standard deviation 0.86). For all-inside devices, defect patterns (n = 436) were 15.6% linear, 38.1% semilunar, 46.3% stellate, while inside-out devices (n = 208) were 95.7% stellate, 4.3% linear, and 0.0% semilunar. All-inside devices had mean defect diameter of 2.46 mm, while inside-out meniscus needles had mean 0.90 mm defect diameter (P < .001). FasT-FIX 360, ULTRA-FAST-FIX, and Arthrex Meniscal Cinch II induced smaller diameter defects than other all-inside devices (F = 20.2, P < .05). Strong positive correlation was found comparing outer needle diameter and mean defect diameters across all devices (R2 = 0.9447). CONCLUSIONS: Needles utilized in meniscal implant systems produce the following basic defect patterns: stellate (62.3%), semilunar (25.8%), and linear (11.9%). A strong positive correlation was found between mean defect size and outer needle diameter across all devices. Inside-out double-armed flexible needles produced significantly smaller defects than all-inside devices. Of the all-inside devices, ULTRA FAST-FIX, FAST-FIX 360, and Arthrex Meniscal Cinch II produced smaller defects on average. CLINICAL RELEVANCE: While the true clinical impact of these findings cannot be drawn from the present study, this investigation provides necessary context to better understand reported similarities and differences in healing rates and outcomes between inside-out and all-inside repair techniques.

Several Techniques Exist With Favorable Biomechanical Outcomes in Radial Meniscus Tear Repair-A Systematic Review.

PURPOSE: To compare biomechanical properties of various radial tear repair techniques in the medial and lateral menisci. METHODS: A search was performed for key words regarding mechanical properties of repair of radial meniscal tears in PubMed, Embase, CINAHL, Scopus, and Cochrane databases, yielding 1791 articles. Articles were screened using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines against inclusion criteria and underwent Methodological Index for Non-Randomized Studies (MINORS) methodologic quality assessment. Repair constructs evaluated were classified based on repair technique, use of a transtibial augmentation, and the number, orientation, and pattern of stitches. Results published across different studies were compared but not subjected to meta-analysis due to variability in testing procedures and heterogeneity of repair methods. RESULTS: We identified 20 studies that performed mechanical testing on 21 different radial meniscal tear repair techniques. The greatest reported mean load-to-failure (LtF) were the transtibial 2-tunnel + 4 horizontal inside-out sutures (191.2 N ± 17.3, cadaver) and all-inside double vertical repair (146.3 N ± 36.2, porcine). The transtibial technique improved LtF and displacement of an inside-out (IO) horizontal repair. All-inside vertical repairs demonstrated greater LtF, stiffness, and displacement compared with IO horizontal repairs in 2 studies. Compared with IO double horizontal repairs, all-inside double vertical or IO double horizontal repairs with reinforcing stitches parallel to the tear exhibited greater LtF in 3 studies and stiffness in 2 studies. Two studies reported that parallel reinforcing stitches significantly reduced suture tear-through compared with similar, nonreinforced repairs. Mean MINORS score for all studies analyzed was 19.88 ± 1.47 points. CONCLUSIONS: A systematic review demonstrated that there may be alternatives to traditional IO horizontal repairs for radial meniscus tears. Less-invasive all-inside vertical techniques reinforced with suture parallel to the tear instead of standard IO horizontal sutures may improve strength of repair. In addition, transtibial 2-tunnel augmentation may also increase strength of radial meniscus tear repairs. CLINICAL RELEVANCE: There may be alternatives to IO horizontal repairs for radial meniscus tears.

Intra-articular steroid injection at the time of knee arthroscopy increases risk of post-operative infection.

PURPOSE: To evaluate the risk of post-operative infection after intra-articular steroid injection at the time of knee arthroscopy at a single institution high-volume sports medicine practice. METHODS: The electronic medical record at a single institution was queried for all patients who underwent knee arthroscopy from 2011 to 2019. Patients were included if they underwent more simple arthroscopic procedures: diagnostic arthroscopy, meniscectomy, loose body removal, synovectomy, or microfracture. Patients were excluded if they underwent more complex procedures, such as ligament reconstruction, meniscus repair, or any open procedures. These patients' medical records were then queried for current procedural terminology and international classification of disease codes indicating post-operative infection. Individual chart review was performed on this group of patients to determine if a true postoperative infection occurred within 6 months of the index arthroscopy. Patients were then categorized into "intra-operative steroid injection" versus "no steroid" based on each surgeon's preferred intra-operative analgesic injection cocktail. RESULTS: A total of 6889 patients were identified, including 2416 (35.1%) who were given intra-articular steroid at the time of knee arthroscopy. Post-operative infection occurred in 10 patients (0.15%) at a median of 18 days (range 9-42 days), 7 who received intra-operative steroid injection (0.29%) and 3 who did not (0.067%), p = 0.040. The relative risk of infection for those who received intra-operative steroid injection was 4.32 times higher than those who did not, with a number needed to harm of 448. There were no significant differences in age, body mass index, smoking status, or the prevalence of diabetes between those who got infected and those who did not. CONCLUSIONS: Knee infection following arthroscopic surgery is rare. Intra-operative steroid injection during arthroscopic knee surgery is associated with a 4.3-fold increased risk of subsequent knee infection. While the overall risk remains low, the use of intra-operative steroids is expected to result in one additional knee infection for every 448 arthroscopic procedures performed. LEVEL OF EVIDENCE: IV.

Orthopaedic Surgery Sports Medicine Fellows See Substantial Increase in Hip Arthroscopy Procedural Volume With High Variability From 2011 to 2016.

PURPOSE: To analyze the trends in operative experience, specifically procedures of the shoulder, hip and knee, of fellows graduating from Accreditation Council for Graduate Medical Education orthopaedic sports medicine fellowships between 2011 and 2016. METHODS: The 2011-2016 Accreditation Council for Graduate Medical Education orthopaedic surgery sports medicine fellow case logs were retrieved for analysis. Trends in the mean case volume for procedures of the shoulder, hip, and knee were analyzed. Linear regression was used to identify significant changes in trends over time for each surgical case/procedure. Variation in case volume between fellows in the lowest (10th) and highest (90th) centile was assessed for first and last year of the study. RESULTS: The average number of total procedures per fellow minimally decreased by 3.5% from 2011 to 2016 (726 to 701 cases) (P < .001). The mean total number of hip procedures significantly increased by 155% from 24.9 to 63.5 (P = .049). There were no significant differences in the mean total number of shoulder (P = .88) and knee procedures (P = .54). Arthroscopic hip procedures had the largest increase from 2011 to 2016 (14.1 to 57.8 [+310%], P = .049). There was greater than 2-fold difference in total procedural volume between fellows in the 10th and 90th percentile for 2011 and 2016, with the greatest variation (64-fold) for arthroscopic hip procedures. CONCLUSIONS: In this study there was a 2.6-fold increase in hip procedures, largely driven by a 310% rise in arthroscopic hip cases. The average procedural volume per fellow minimally decreased, with no change in the mean number of shoulder and knee procedures. CLINICAL RELEVANCE: Understanding variability in case exposure among orthopaedic sports medicine fellowships is important for programs to ensure that fellows are appropriately exposed to all facets of sports medicine procedures.

Safety and Efficacy of an Amniotic Suspension Allograft Injection Over 12 Months in a Single-Blinded, Randomized Controlled Trial for Symptomatic Osteoarthritis of the Knee.

PURPOSE: The purpose of this study is to determine the efficacy of amniotic suspension allograft (ASA) compared to hyaluronic acid (HA) and saline at up to 12 months of follow-up through the use of patient-reported outcomes, immunoglobulin levels, and anti-human leukocyte antigen (HLA) levels. METHODS: Within this multicenter study, 200 patients were randomized 1:1:1 to a single intra-articular injection of saline, HA, or ASA. Patient-reported outcomes, including Knee Injury and Osteoarthritis Outcome Score (KOOS) and visual analog scale (VAS) score, were collected at multiple time points (baseline, 1 week, 6 weeks, 3 months, 6 months) out to 12 months to assess improvements in pain and function. Radiographs at baseline and 12 months were taken to determine radiographic changes, while blood was collected at baseline, 6 weeks, and 6 months to determine changes in immunoglobulins and anti-HLA levels. Statistical analyses were performed using last observation carried forward and mixed effects model for repeated measures. RESULTS: Treatment with ASA resulted in significant improvements in KOOS and VAS scores that were maintained through 12 months (P < .05). Treatment with ASA resulted in a 63.2% responder rate at 12 months using the Outcome Measures in Arthritis Clinical Trials-Osteoarthritis Research Society International simplified definition. There were no significant differences between groups for radiographic measures in the index knee, immunoglobulins, C-reactive protein, or anti-HLA serum levels (P > .05). The number and type of adverse events (AEs) reported for ASA were comparable to the HA injection group, while no treatment-emergent AEs were reported for the saline group. CONCLUSIONS: This randomized controlled trial of ASA vs HA and saline for the treatment of symptomatic knee osteoarthritis demonstrated clinically meaningful improved outcomes with ASA over the controls out to 12 months postinjection. No concerning immunologic or adverse reactions to the ASA injection were identified with regards to severe AEs, immunoglobulin, or anti-HLA levels. LEVEL OF EVIDENCE: Level I, randomized controlled multicenter trial.

Editorial Commentary: Anterior Cruciate Ligament Autograft Morbidity: Who Needs Strong Hamstrings in Greater Than 90° of Knee Flexion?

An understanding of expected morbidity of various anterior cruciate ligament graft options is important to inform patient expectations and facilitate successful return to sport following anterior cruciate ligament reconstruction. Hamstring harvest results in decreased hamstring strength. Gracilis preservation may mitigate the degree of strength loss, particularly in deep knee flexion. The extent to which knee flexion strength at high flexion angles is important to return to play and functional outcomes remains unknown and is likely sport-dependent.

Patient Outcomes After Horizontal Cleavage Tear Repair: A Systematic Review.

PURPOSE: To analyze the clinical outcomes and survivorship of meniscal horizontal cleavage tear (HCT) repairs with hopes of guiding future treatment decisions. METHODS: Standard systematic review methodology was used. A comprehensive search of PubMed was conducted on June 1, 2019. The inclusion criteria were articles that were published in English, involved human subjects, and reported on at least 1 outcome after repair of HCTs. The exclusion criteria included technique guides and reviews, studies without full text available, and studies with HCT outcomes not separated from other repair groups. Effect heterogeneity was determined using the I2 measure. Forest plots were created in addition to a random-effects model to show the results. RESULTS: The systematic review yielded 19 studies evaluating 289 knees in a total of 273 patients. At most recent follow-up, there was a high probability of return to sport (93.1% [67 of 72]). Overall, 74% of patients (67 of 90) were symptom free at last follow-up, and 80% expressed satisfaction with their overall result (80 of 100). The most frequently reported subjective outcome was the Lysholm score, which improved from a preoperative study range of 48 to 79 (I2 = 20.7%, P = .283) to a postoperative study range of 56 to 99 (I2 = 49%, P = .081). The next most commonly reported was the International Knee Documentation Committee subjective score, which improved from a preoperative study range of 16 to 49 (I2 = 47.7%, P = .125) to a postoperative study range of 72 to 95 (I2 = 0%, P = .660). An overall 11.7% reported risk of reoperation was found, with most cases involving revision meniscectomy. Rates of complications beyond fixation failure were overall very low, with infrequent reports of septic arthritis and transitory dysesthesia. CONCLUSIONS: The short- to intermediate-term results of repair of HCTs are comparable to prior studies. Survivorship is comparable to repairs of other types of meniscal tears with high rates of return to sport and low complication rates. LEVEL OF EVIDENCE: Level IV, systematic review of Level I-IV studies.

Subjective Knee Function and Risk of Failure Are Equivalent for Men and Women at 5 Years After Meniscus Repair.

PURPOSE: To determine whether subjective knee function or risk of repair failure differ between men and women at mean 5 years following meniscal repair with or without concomitant anterior cruciate ligament reconstruction. METHODS: A total of 235 patients (97 women, 138 men; mean age, 29.1 years; standard deviation, 11.3) were assessed for meniscus repair failure and postoperative knee function at mean 5.8 years follow-up. Knee symptoms were assessed with International Knee Documentation Committee Subjective (IKDC-S) scores. Postoperative activity scores were assessed with Marx activity score. Independent effects of patient age and activity level on meniscus failure risk and patient-reported outcomes were determined by multivariate analysis with adjustment for age, body mass index, anterior cruciate ligament status, tear pattern, and number of implants used at the time of surgery. RESULTS: Failures occurred in 18.9% of men and 21.0% of women with no difference in mean time to failure (P = .75) or risk of failure for men vs women (P = .57) in the univariate analysis. Male sex was not an independent risk factor for failure after adjustment for patient age, body mass index, concomitant anterior cruciate ligament status, tear pattern, or number of implants used (P = .16). Marx activity scores at follow-up were higher among men in multivariate analysis (P = .009). Men and women had similar IKDC-S scores at follow-up in the unadjusted (P = .25) and multivariate analyses (P = .21). CONCLUSIONS: Following meniscus repair, both sexes report similar subjective knee function, though men have higher self-reported activity scores. Meniscus repair failure risk does not differ between men or women at mid-term follow up. LEVEL OF EVIDENCE: Level III, retrospective case-control study.

Medial patellofemoral ligament reconstruction with allograft versus autograft tissue results in similar recurrent dislocation risk and patient-reported outcomes.

PURPOSE: To determine the rate of recurrent dislocation and patellar instability following medial patellofemoral ligament (MPFL) reconstruction with allograft or autograft tissue and compare patient-reported outcomes for patients undergoing allograft and autograft MPFL reconstruction. METHODS: One hundred and fifteen MPFL reconstructions (78 allograft, 37 autograft) without concurrent bony procedures performed between 2008 and 2014 by four sports medicine fellowship-trained orthopedic surgeons at our center were identified. Patient demographics and surgical data were identified by chart review. Chart review and patient interviews were undertaken to identify recurrent patellar dislocations and as recurrent subjective patellofemoral instability. Recurrent dislocation and subjective instability risk were compared between the allograft and autograft groups. RESULTS: Eighty-seven patients (76%) with complete baseline data and minimum 1-year follow-up were contacted at a mean of 4.1 years following isolated MPFL reconstruction, including 57 patient with allograft reconstructions and 30 with autograft reconstructions. No significant differences in patient sex, age at reconstruction, body mass index, or time to follow-up were noted between groups. Recurrent dislocation occurred in 2 patients in the allograft group (3.5%) and 1 patient in the autograft group (3.3%), (n.s.). Recurrent subjective instability occurred in 17 patients in the allograft group (28.9%) and 11 patients in the autograft group (36.7%), (n.s.). No significant differences in patient-reported outcomes were noted between groups. CONCLUSION: The use of either allograft or autograft tissue for MPFL reconstruction results in low (< 3%) risk of recurrent patellar dislocation. Risk of recurrent subjective instability is higher but is similar for both graft types. Surgeons can utilize either graft choice at their discretion without anticipating a significant impact of graft choice on patient outcomes. LEVEL OF EVIDENCE: III.

Femoral nerve block at time of ACL reconstruction causes lasting quadriceps strength deficits and may increase short-term risk of re-injury.

PURPOSE: To determine whether femoral nerve blockade (FNB) at the time of primary ACL reconstruction is associated with meeting isokinetic extension strength return to sport criteria near completion of physical therapy and whether FNB affects 1-year or 2-year risk of ipsilateral ACL graft rupture or contralateral native ACL injury. METHODS: Three-hundred and sixty patients (n = 244 with FNB, n = 116 no FNB) underwent primary ACL reconstruction. All patients completed rehabilitation and underwent functional strength testing towards the end of knee rehabilitation (mean 5.6 months post-surgery). Association between FNB and isokinetic extension strength limb symmetry index (LSI) (goal LSI ≥ 90% for return to sport) as well as risk of recurrent ACL injury within first or second year after surgery was evaluated. RESULTS: Ipsilateral or contralateral ACL injury within 2 years occurred in 11.2% of patients with FNB and 5.7% without FNB (p = 0.01). Patients with FNB had higher incidence of ipsilateral graft rupture within the first year after surgery but no difference in graft rupture during the second. Two-year risk of contralateral ACL injury was similar in both groups. At the time of initial testing, patients who received FNB had lower fast isokinetic extension LSI versus patients without FNB and were less likely achieve a goal ≥ 90% LSI; slow extension LSI was unaffected. CONCLUSION: Use of FNB at the time of primary ACL reconstruction can negatively affect achievement of isokinetic extension strength return to sport criteria. FNB increases risk of graft rupture within the first year after surgery but does not affect re-injury risk during the second. FNB may not be appropriate for use in patients already at high risk of ACL re-injury. LEVEL OF EVIDENCE: III.

Meniscal allograft transplantation: a review of indications, techniques, and outcomes.

When compared to meniscectomy, meniscus allograft transplantation (MAT) may provide superior long-term benefits to young, active patient populations who have lost meniscal function because of irreparable damage, such as, an avascular tear, previous repair failure, and unsalvageable tear types. Positive outcomes are most likely to be achieved when meniscus allograft transplantation is performed in appropriately selected patients. Indications include patients younger than 50 years of age, with a history of subtotal or total meniscectomy without concomitant articular cartilage defects, uncorrectable joint malalignment, and/or knee instability. Outcomes for meniscal allograft transplantation are promising with studies reporting long-term graft survivorship as high as 89% at 10 years and significant improvements in multiple patient reported outcome measures. LEVEL OF EVIDENCE: Level V.

Cartilage damage at the time of anterior cruciate ligament reconstruction is associated with weaker quadriceps function and lower risk of future ACL injury.

PURPOSE: To determine whether articular cartilage damage noted at the time of primary anterior cruciate ligament reconstruction (ACLR) affects the likelihood of achieving ≥ 90% symmetry for isokinetic extension strength at 6 months after surgery or risk of recurrent ACL injury. METHODS: Five hundred and eight patients underwent primary ACLR and diagnostic arthroscopy. All identified cartilage lesions were graded using the Outerbridge system. All patients underwent isokinetic strength testing. The association between cartilage Outerbridge grade and a ≥ 90% Limb Symmetry Index (LSI) and recurrent ACL injury risk at mean 38.7 month follow-up (SD 31.8) was evaluated via multivariate regression analysis. RESULTS: Grade 2 or higher damage was present in 394 (77.5%) of patients, grade 3 or higher in 143 (28.1%) and grade 4 in 83 (16.4%) at time of ACLR. Ipsilateral ACLR graft rupture occurred in 31 (6.1%) of patients. Contralateral ACL injury occurred in 19 (3.7%). Patients with grade 2 or higher damage were significantly less likely to meet an LSI goal of ≥ 90% for fast (300°/s) isokinetic extension. There was no association with slow isokinetic extension. Cartilage lesion severity at or beyond grade 2 had a similar effect on isokinetic testing results regardless of compartment involvement or performance of microfracture. Patients with grade 2-4 cartilage damage were less likely to sustain a second ipsilateral ACL injury or a contralateral native ACL injury. CONCLUSIONS: Cartilage damage seen at time of ACL reconstruction is common and associated with lower likelihood of achieving ≥ 90% symmetry for isokinetic extension strength at 6 months after surgery. However, lower recurrent ACL injury rates are seen in patients with concurrent cartilage damage. These data may inform future clinical decisions regarding operative managment of recurrent ACL injuries. LEVEL OF EVIDENCE: III.

The effect of perioperative platelet-rich plasma injections on postoperative failure rates following rotator cuff repair: a systematic review with meta-analysis.

BACKGROUND: Platelet-rich plasma (PRP) has gained significant interest in recent years to potentially add biological augmentation of healing to surgical repairs of soft-tissue injuries. We sought to determine whether perioperative PRP injection influences the risk of failure following rotator cuff repair. METHODS: A systematic search was performed in the Embase and PubMed databases and identified 16 randomized controlled trials or prospective cohort studies (1045 participants) reporting rates of failure, defined as a subsequent tear on postoperative imaging, after rotator cuff repair with or without perioperative PRP administration. A random-effects meta-analysis of the included studies was performed to determine the pooled effect of PRP administration on the postoperative failure risk. RESULTS: Among the 16 studies investigating rotator cuff repairs, PRP augmentation resulted in a 25% reduction in the risk of repair failure, with low heterogeneity among the included studies. A significant protective effect was seen for studies of only small to medium tears (7 studies) (P = .007) and studies including large or massive tears (9 studies) (P < .001). CONCLUSIONS: Intraoperative PRP reduces the failure risk following rotator cuff repair and has a consistent effect regardless of tear size. However, because of the variability in PRP preparations, a specific recommendation cannot be made.

Psychological Assessment Tools Utilized in Sports Injury Treatment Outcomes Research: A Review.

The use of self-report psychological assessment tools in outcomes research has become increasingly frequent, though many sports medicine providers and researchers are unfamiliar with these instruments. We conducted a systematic search of the sports medicine literature in PubMed, Scopus, SPORTDiscus, and Google Scholar of studies published on or before November 1st, 2019. Included psychological self-assessment tools were limited to those in a written self-assessment format and were used in musculoskeletal sports injury or concussion treatment outcome studies. Both pre- or post-treatment psychological assessments were included. Thirty-four assessment scales of psychological factors were utilized across 152 sports injury treatment outcomes studies. Six assessment tools were utilized in 5 or more studies and the remaining 28 were utilized in 4 or fewer studies. Many of the utilized scales have adequate assessment and reporting of internal consistency reliability, supporting further reliability and validation studies for use in sports injury treatment outcomes research.