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.

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.

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.

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.

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.

Medial patellofemoral ligament reconstruction for recurrent patellar dislocation allows a good rate to return to sport.

PURPOSE: Recurrent patellar dislocation is a frequent knee disorders in young, active patients. Medial patellofemoral ligament reconstruction (MPFLR) can restore knee stability and function, but the rate of return to sports is less clear. The aim of this study was to evaluate rate of return to sport following treatment of recurrent patellar dislocation with isolated MPFLR. METHODS: Between 2011 and 2018, 113 patients with recurrent patellar dislocation were treated with isolated MPFLR at an academic center. Pre-injury sports participation and Tegner score, pre-operative subjective IKDC score, time to return to sports, and post-operative Tegner and subjective IKDC scores were collected, with a minimum of follow-up of 2 years. RESULTS: One hundred and three patients (91%) were evaluated at a mean of 4.5 ± 2.5-year post-operative. 92 patients (89%) participated in sports prior to onset of patellar instability. At final follow-up, 84 of these 92 patients (91%) were able to return to sports. The mean time from surgery to return to sports was 10.4 ± 8.6 months (range: 2-48 months). 62 patients (67%) returned to the same (50 patients) or higher (12 patients) level. 22 patients (26%) returned at a lower level. 19 of these patients attributed this decreased participation to ongoing knee problems. The median Tegner score was noted to decrease from 5 pre-injury to 4 post-operatively (p = 0.02). CONCLUSION: Isolated MPFL reconstruction allowed return to pre-injury sports in 91% of patients, with 67% of patients returning to the same or higher level than pre-injury. Mean time to return to sports was 10 months and post-operative Tegner score was noted to be modestly decreased from pre-injury level. LEVEL OF EVIDENCE: IV.

Treatment of Chronic Proximal Hamstring Tendinopathy with Surgical Debridement and Suture Anchor Repair.

We evaluated outcomes following surgical debridement and suture anchor repair of chronic proximal hamstring tendinopathy without sciatic nerve decompression. Chart review identified eight patients (one bilateral) who met study requirements. All eight patients were available for follow-up at a mean of 6.7 years and none underwent re-operation on the index hip during the follow-up period. Seven patients completed patient-reported outcome scores. The mean LEFS score was 81.1, and the mean SANE score was 74.9. The mean Marx activity score was 2.8, and the mean Custom Marx score was 23.3. Pain relief was excellent. The mean numeric pain score at rest was 0.6, while the mean numeric pain score with activity was 4.0. Treatment of chronic, recalcitrant proximal hamstring tendinopathy with surgical debridement and suture anchor repair without exploration of the sciatic nerve results in excellent pain relief, good function, and low re-operation risk. (Journal of Surgical Orthopaedic Advances 31(1):061-064, 2022).

ACL Study Group survey reveals the evolution of anterior cruciate ligament reconstruction graft choice over the past three decades.

PURPOSE: Anterior cruciate ligament reconstruction (ACLR) aims to restore knee function and stability, allowing patients to return to the activities they enjoy and minimize further injury to the meniscus and cartilage and their ultimate progression to osteoarthritis. This study aims to present the evolution of graft choice over the last three decades according to members of the ACL Study Group (SG). METHODS: Prior to the January 2020 ACL SG biannual meeting, a survey was administered consisting of 87 questions and 16 categories, including ACLR graft choice. A similar questionnaire has been administered prior to each meeting and survey results from the past 14 meetings (1992 through 2020, excluding 1994) are included in this work. Survey responses are reported as frequencies in percentages to quantify changes in practice over the surgery period. RESULTS: In 1992, the most frequent graft choice for primary ACLR was bone-patellar tendon-bone (BTB) autograft, at nearly 90%. Hamstring tendon (HT) autografts have increased in popularity, currently over 50%, followed by just under 40% BTB autograft. Recently, quadriceps tendon (QT) autograft has increased in popularity since 2014. CONCLUSION: Autograft (HT, BTB, QT) is an overwhelming favorite for primary ACLR over allograft. The preference for HT autograft increased over the study period relative to BTB autograft, with QT autograft gaining in popularity in recent years. Graft selection should be individualized for each patient and understanding the global trends in graft choice can help orthopaedic surgeons discuss graft options with their patients and determine the appropriate graft for each case. LEVEL OF EVIDENCE: Level V, Expert Opinion.

Editorial Commentary: So Your Knee Has a Big Pivot Shift Before Anterior Cruciate Ligament Surgery-Why Does that Matter???

Control of anterolateral knee laxity has always been a major goal of anterior cruciate ligament (ACL) reconstruction. The recent focus on the anatomy of the anterolateral knee and new studies demonstrating decreased graft failure risk with the additional of lateral procedures to intra-articular ACL reconstruction have given these procedures new relevance. A key question that drives indications is which patients benefit the most from these procedures. Those patients with increased rotational knee laxity, particularly in the absence of a repairable meniscus injury, may be good candidates. ACL injury chronicity, bony anatomy, concomitant anterolateral injury, and other factors all contribute to increased anterolateral knee laxity. This high laxity population is ideal for evaluation of the effectiveness of new methods to control knee laxity and improve outcomes of isolated intra-articular ACL reconstruction.

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.

Editorial Commentary: The Trend to Blend: Should We Be Using Hybrid Grafts in Adult Anterior Cruciate Ligament Reconstructions?

Hybrid anterior cruciate ligament grafts augmenting a small-diameter hamstring tendon autograft with nonirradiated allografts can be used with good results in adults. In teens, however, outcomes of hybrid grafts have not been well defined, and other solutions to small hamstring grafts including graft folding, contralateral autograft augmentation, or selection of a different autograft source could be considered.

Age of 40 Years or Older Does Not Affect Meniscal Repair Failure Risk at 5 Years.

PURPOSE: To compare meniscal repair failure rates in patients aged 40 years or older versus patients younger than 40 years. METHODS: A total of 276 patients underwent meniscal repair surgery by a single sports medicine fellowship-trained surgeon between 2006 and 2012 and were eligible for study inclusion. Patients were followed up for meniscal repair failure, defined as meniscectomy, repeated meniscal repair, or total knee arthroplasty. Logistic regression analysis was used to determine the risk of failure while controlling for potential confounding variables including body mass index, sex, anterior cruciate ligament status, time from injury to surgery, number of implants used, tear pattern, and chondral status at the time of the repair. RESULTS: Among the 276 eligible patients, 221 (80%) were successfully contacted for follow-up at an average of 5 years after surgery. Of these patients, 56 were aged 40 years or older (mean, 47.2 years; standard deviation [SD], 5.3 years) and 165 were younger than 40 years (mean, 24.7 years; SD, 6.7 years). The overall meniscal repair failure rate over a 5-year period was 20%. Among patients aged 40 years or older, the failure risk was 18% versus 21% in patients younger than 40 years. After adjustment for confounding variables, age of 40 years or older was not associated with increased failure risk (adjusted odds ratio, 0.83; 95% confidence interval, 0.36-1.81; P = .65). The mean time to failure tended to be shorter in older patients, at 16.9 months (SD, 10.2 months) versus 28.5 months in the group younger than 40 years (SD, 23.3 months) (P = .04). CONCLUSIONS: Age of 40 years or older is not associated with an increased risk of meniscal repair failure at 5 years, although a shorter time to failure was noted in this age cohort. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Biomechanical Properties of Posterior Meniscal Root Repairs: A Systematic Review.

PURPOSE: To systematically review the literature regarding the biomechanical properties of various meniscal root repair techniques. METHODS: A systematic review of multiple databases was performed. The inclusion criteria included English language, studies relevant to meniscal root repairs, studies comparing 2 or more different discrete techniques, posterior root repairs, controlled laboratory studies, and human cadaveric or animal studies. Abstracts, case reports, cohort studies, case-control studies, systematic reviews and meta-analyses, and studies of meniscal body repairs were excluded. RESULTS: Seventeen controlled laboratory studies were included for final analysis. There is no consensus on biomechanical superiority between transtibial pullout repair (TPR) and suture anchor repair. For TPR, there is no significant difference between 1 and 2 tibial tunnels. Nonanatomic repairs result in significantly lower joint surface contact areas and higher contact pressures, but suture placement farther from the root results in higher maximum load to failure. Two-suture repair has a greater maximum load to failure than 1-suture repair. Use of more than 2 sutures has diminishing returns. The modified Mason-Allen suture configuration is superior to a simple suture configuration, but there is no consensus regarding the superiority or feasibility of more complex sutures. There is no consensus on the superiority of a single suture material or shape. CONCLUSIONS: Anatomic meniscal root repairs with either TPR or suture anchor repair have better joint surface contact pressures and contact surface areas than nonanatomic repairs. The use of 2 sutures results in better fixation than 1 suture. There is evidence that the modified Mason-Allen suture configuration is superior to a simple suture configuration in a TPR, although the benefits of more complicated configurations are unclear. CLINICAL RELEVANCE: This study suggests that, in general, more complex sutures exhibit higher maximum loads. Increasing the number of sutures to up to 2 of the same configuration also increases the maximum load.

Lateral retinacular release is not recommended in association to MPFL reconstruction in recurrent patellar dislocation.

PURPOSE: Reconstruction of the medial patellofemoral ligament (MPFL) has become the gold standard for the treatment of the recurrent patellar dislocation (RPD). Lateral retinacular release can be performed in association with MPFL reconstruction, but the effect on outcomes is not clear. To evaluate the effect of lateral release on outcomes following MPFL reconstruction is the aim of this study. It is hypothesized that isolated MPFL reconstruction was not inferior to MPFL reconstruction and lateral retinacular release in terms of IKDC subjective score and patellar tilt (PT). METHODS: Patients between ages 18 and 45 scheduled to undergo MPFL reconstruction without an associated bony procedure (tibial tubercle osteotomy or trochleoplasty) were randomized to isolated MPFL reconstruction or MPFL reconstruction (no LRR group) and arthroscopic LRR (LRR group). Evaluation criteria were subjective IKDC score as the primary outcome and PT evaluated with a CT-scan. PT was evaluated with the quadriceps relaxed (PTQR) and contracted (PTQC). RESULTS: Of 43 patients included in the trial, 7 were lost of follow-up, 3 were not able to complete evaluation because of medical reasons, and 33 patients were evaluated with a minimum of 12 months and a median follow-up of 24 (12-60) months. The average subjective IKDC score was at 86 ± 20 (29-94) in the LRR group and 82 ± 15 (39-95) in the no LRR group (p = 0.45). The PTQR was at 22° ± 7° (13-37) in the LRR group and 21 ± 10 (4-37) in the no LRR group (n.s.). The PTQC was at 27° ± 9° (12-40) in the LRR group and 25 ± 12 (5-45) in the no LRR group (n.s.). No complications were noted in either group. CONCLUSIONS: No significant differences were found in subjective IKDC score or patellar tilt based on the addition of an arthroscopic LRR to an MPFL reconstruction in patients with RPD not undergoing associated bony procedures. There is no indication to a systematic lateral retinacular release in association with MPFL reconstruction in the treatment of RPD. LEVEL OF EVIDENCE: II.

Accelerated rehabilitation results in good outcomes following acute repair of proximal hamstring ruptures.

PURPOSE: To assess outcomes of patients who underwent proximal hamstring repair utilizing an accelerated rehabilitation protocol with immediate weight bearing as tolerated and no bracing. METHODS: Retrospective chart review identified 47 proximal hamstring tendon repairs with suture anchors in 43 patients performed during 2008-2015. Rehabilitation included no immobilization or limited weightbearing. Patients were contacted by phone to assess outcomes utilizing the lower extremity functional score (LEFS), single-assessment numeric evaluation (SANE), and Marx activity scale. Overall patient-reported scores were calculated and results of acute and chronic repairs compared. RESULTS: Thirty-four patients (38 repairs, 80.8%) were available for follow-up at mean of 4.1 ± 2.0 years following repair. There were two re-tears: one complete rupture 5 weeks postoperative and one partial rupture 10 weeks postoperative in the chronic group. Patients in general reported low pain and good function with a mean LEFS score of 87 ± 21%, a mean SANE score of 88.1 ± 11.6, and a mean numeric pain score of 8.5 ± 15.3 in the last week and 12.2 ± 21.1 with activity. The acute repair group was noted to have a higher mean LEFS score (93.7 versus 79.8%, p = 0.004) and SANE score (91.3 versus 83.8, p = 0.047), and lower pain with activity (21.7 versus 4.8, p < 0.001) as compared to the chronic group. CONCLUSIONS: Repair of acute proximal hamstring ruptures results in good function and pain relief with the use of a rehabilitation protocol that does not require weight-bearing restrictions or bracing. LEVEL OF EVIDENCE: III, therapeutic.

Bacterial DNA is associated with tunnel widening in failed ACL reconstructions.

PURPOSE: To determine if tunnel widening, defined as change in maximal tunnel diameter from the time of initial bone tunnel drilling to revision surgery is associated with bacterial deoxyribonucleic acid (DNA) presence and concentration in torn graft tissue from failed anterior cruciate ligament reconstructions (ACLRs). METHODS: Thirty-four consecutive revision ACLRs were included (mean age 27.3 years SD 10.9; median time to failure 4.9 years range 105 days-20 years). Graft selection of the failed reconstruction was 68% autograft, 26% allograft, and 6% autograft/allograft hybrid with a mean drilled tunnel diameter of 8.4 mm SD 0.8. Maximal tunnel diameters prior to revision were measured on pre-operative three-dimensional imaging and compared to drilled tunnel diameters at the time of the previous reconstruction. Tissue biopsies of the failed graft were obtained from tibial, femoral, and intraarticular segments. Sterile water left open to air during revision ACLRs and tissue from primary ACLRs were used as negative controls. Clinical cultures were obtained on all revision ACLRs and PCR with universal bacterial primer on all cases and negative controls. Fluorescence microscopy was used to confirm the presence and location of biofilms in two patients with retrieved torn graft tissue and fixation material. Amount of tunnel widening was compared to bacterial DNA presence as well as bacterial DNA concentration via Welch ANOVA. RESULTS: Bacterial DNA was present in 29/34 (85%) revision ACLRs, 1/5 (20%) of primary ACLR controls and 0/3 (0%) sterile water controls. Cultures were positive (coagulase negative Staphylococcus sp.) in one case, which also had the greatest degree of tunnel widening. Femoral widening was greater in cases with detectable bacterial DNA (mean widening 2.6 mm SD 3.0) versus without (mean 0.3 mm SD 0.6) (p = 0.003) but was unaffected by bacterial DNA concentration (p = 0.44). Tibial widening was not associated with the presence of bacterial DNA (n.s.); however, higher bacterial DNA concentrations were observed in cases with tibial widening ≥ 3.0 mm (median 2.47 ng bacterial DNA/µg total DNA) versus widening < 3.0 mm (median 0.97 ng bacterial DNA/µg total DNA) (p = 0.046). Tunnel widening was not associated with time to failure, graft selection, or number of prior surgeries (n.s., all comparisons). Fluorescence microscopy confirmed the presence of biofilms on ruptured tendon graft as well as fixation material in 2/2 cases. CONCLUSION: Bacterial DNA is commonly encountered on failed ACLR grafts and can form biofilms. Bacterial DNA does not cause clinically apparent infection symptoms but is associated with tunnel widening. Further research is needed to determine whether graft decontamination protocols can reduce graft bacterial colonization rates, ACLR tunnel widening or ACLR failure risk. LEVEL OF EVIDENCE: Therapeutic III.