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Background: Approximately 100,000 anterior cruciate ligament (ACL) reconstructions (ACLRs) occur annually in the United States, and postoperative surgical-site infection is a relatively rare but devastating complication, often leading to graft failure or septic arthritis of the knee, necessitating repeat surgery. Wrapping allografts in vancomycin-soaked gauze has been adopted as a common sterilization technique in the operating room to reduce surgical-site infection; however, identifying effective alternatives to vancomycin has not been extensively pursued. Hypothesis: Tobramycin would be as effective as vancomycin in reducing the concentrations of Staphylococcus epidermidis bacteria on tendon allografts. Study Design: Controlled laboratory study. Methods: S. epidermidis strain ATCC 12228 was inoculated onto the human cadaveric gracilis tendon. The tendons were wrapped in sterile gauze saturated with tobramycin or vancomycin at various experimental concentrations. Bacteria remaining on the tendon were dislodged, serially diluted, and plated for colony counting. Statistical analysis was performed utilizing 2-way analysis of variance testing. Results were considered statistically significant when P <.05. Results: Vancomycin (P =.0001) and tobramycin (P <.0001) reduced bacterial concentration. Tobramycin was found to produce a statistically significant reduction in bacterial concentration at concentrations as low as 0.1 mg/mL (P <.0001 and P =.01 at 10 and 20 minutes), while vancomycin produced a statistically significant reduction at a concentration as low as 2.5 mg/mL (P <.0001 at both 10 and 20 minutes). Conclusion: This study demonstrates that tobramycin is as effective as vancomycin in bacterial concentration reduction but can achieve this reduction level at lower doses. Further studies clarifying the biomechanical and cytotoxic effects of tobramycin on tendon tissue are indicated to solidify its use as a clinical alternative to vancomycin in ACLR. Clinical Relevance: These results will begin establishing tobramycin as an alternative to vancomycin in ACL graft decontamination. Because of relatively frequent shortages of vancomycin, establishing tobramycin as an alternative agent is a useful option for the orthopaedic surgeon. [ABSTRACT FROM AUTHOR]

Background: Predictors of return to activity after anterior cruciate ligament reconstruction (ACLR) among patients with relatively high preinjury activity levels remain poorly understood. Purpose/Hypothesis: The purpose of this study was to identify predictors of return to preinjury levels of activity after ACLR, defined as achieving a Marx activity score within 2 points of the preinjury value, among patients with Marx activity scores of 12 to 16 who had been prospectively enrolled in the Multicenter Orthopaedic Outcomes Network (MOON) cohort. We hypothesized that age, sex, preinjury activity level, meniscal injuries and/or procedures, and concurrent articular cartilage injuries would predict return to preinjury activity levels at 2 years after ACLR. Study Design: Cohort study; Level of evidence, 2. Methods: All unilateral ACLR procedures from 2002 to 2008 performed in patients enrolled in the MOON, with preinjury Marx activity scores ranging from 12 to 16, were evaluated with a specific focus on return to preinjury activity levels at 2 years postoperatively. Return to activity was defined as a Marx activity score within 2 points of the preinjury value. The proportion of patients able to return to preinjury activity levels was calculated, and multivariable modeling was performed to identify risk factors for patients' inability to return to preinjury activity levels. Results: A total of 1188 patients were included in the final analysis. The median preinjury Marx activity score was 16 (interquartile range, 12-16). Overall, 466 patients (39.2%) were able to return to preinjury levels of activity, and 722 patients (60.8%) were not able to return to preinjury levels of activity. Female sex, smoking at the time of ACLR, fewer years of education, lower 36-Item Short Form Health Survey Mental Component Summary scores, and higher preinjury Marx activity scores were predictive of patients' inability to return to preinjury activity levels. Graft type, revision ACLR, the presence of medial and/or lateral meniscal injuries, a history of meniscal surgery, the presence of articular cartilage injuries, a history of articular cartilage treatment, and the presence of high-grade knee laxity were not predictive of a patient's ability to return to preinjury activity level. Conclusion: At 2 years after ACLR, most patients with high preinjury Marx activity scores did not return to their preinjury level of activity. The higher the preinjury Marx activity score that a patient reported at the time of enrollment, the less likely he/she was able to return to preinjury activity level. Smoking and lower mental health at the time of ACLR were the only modifiable risk factors in this cohort that predicted an inability to return to preinjury activity levels. Continued effort and investigation are required to maximize functional recovery after ACLR in patients with high preinjury levels of activity. [ABSTRACT FROM AUTHOR]

Background: Anterior cruciate ligament (ACL) reconstruction is a common orthopedic surgery, and due to the increased number of primary reconstructions being performed, the number of revision ACL reconstructions is also increasing. Indications: Two-stage revision ACL reconstruction has lower failure rates compared to 1-stage and is indicated when significant tunnel expansion has occurred or malpositioned tunnels prohibit an adequate reconstruction. In this presentation, 2-stage revision ACL reconstruction was performed with an arthroscopic bone grafting technique of both the femoral and tibial tunnels secondary to tunnel osteolysis. Technique Description: Standard diagnostic arthroscopy is performed, and any chondral or meniscal pathology is addressed. The remnant ACL graft and all hardware are removed. The tunnels are debrided thoroughly. Using a modified syringe, the tunnels are packed with a mixture of cancellous bone chips and cortical fibers that have been hydrated with whole blood and platelet-rich plasma (PRP). The patient is placed into a brace postoperatively, and a computed tomography (CT) is obtained approximately 4 to 6 months postoperatively to assess for bone healing. Revision ACL reconstruction is performed once indicated with standard rehabilitation and return to play protocol. Results: Both 1-stage and 2-stage revision ACL reconstructions have been demonstrated to have significant improvement in outcomes scores preoperatively to postoperatively. However, 2-stage has lower failure rates compared to single-stage and has a high return to level of play. Discussion/Conclusion: Revision ACL reconstruction is becoming more commonly performed, and 2-stage revision is frequently required due to multiple factors. In this video, we demonstrate bone grafting for revision ACL reconstruction for tunnel osteolysis. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication. Graphical Abstract This is a visual representation of the abstract. [ABSTRACT FROM AUTHOR]

Background: Elevated posterior tibial slope (PTS) has been identified as an important risk factor in anterior cruciate ligament (ACL) injuries and ACL graft failures. The cutoff value to recommend treatment with slope-reducing osteotomy remains unclear and is based on expert opinion and small case series. Purpose: (1) To determine whether there is a difference in PTS shown on lateral knee radiographs and magnetic resonance imaging (MRI) scans in a group of patients who experienced revision ACL graft failure versus a control group of patients who underwent successful revision ACL reconstruction, (2) to identify cutoff values of PTS measurements that predict risk of revision ACL graft failure, and (3) to examine whether there is a correlation between radiographic and MRI measurements of PTS. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 38 patients who experienced revision ACL graft failure were identified from a revision ACL database. These patients were matched 1:1 by age, sex, and graft type to a group of 38 control patients who underwent revision ACL reconstruction with no evidence of graft failure at a minimum 2 years of follow-up. Medial and lateral PTS were measured by lateral knee radiographs and MRI scans of the affected limb. Demographics, surgical characteristics, and PTS were compared between the groups. The optimal cutoff values of medial and lateral PTS per radiographs and MRI scans for predicting increased risk of revision ACL graft failure were determined by receiver operating characteristic curves. Conditional multivariable logistic regression was used to assess the relative contribution of PTS cutoff values as a predictor of revision graft failure. Results: The mean PTS values in the failure group were significantly higher than those in the control group on radiographs (medial, 13.2°± 2.9° vs 10.3°± 2.9°; P <.001; lateral, 12.9°± 3.0° vs 9.8°± 2.8°; P <.001) and MRI scans (medial, 7.2°± 3.1° vs 4.8°± 2.9°; P <.001; lateral, 8.4 ± 3.1° vs 5.9 ± 3.0°; P <.001). A radiographic medial PTS ≥14° had the highest increased risk of revision ACL graft failure with sensitivity equal to 50% and specificity to 92.1% (odds ratio, 18.71; 95% CI, 2.0-174.9; P =.01). Conclusion: Elevated PTS was a significant risk factor for revision ACL graft failure. Patients with radiographic medial PTS ≥14° had 18.7-times increased risk of revision ACL failure. [ABSTRACT FROM AUTHOR]

Background: Articular cartilage and meniscal damage are commonly encountered and often treated at the time of anterior cruciate ligament reconstruction (ACLR). Our understanding of how these injuries and their treatment relate to outcomes of ACLR is still evolving. Hypothesis/Purpose: The purpose of this study was to assess whether articular cartilage and meniscal variables are predictive of 10-year outcomes after ACLR. We hypothesized that articular cartilage lesions and meniscal tears and treatment would be predictors of the International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS) (all 5 subscales), and Marx activity level outcomes at 10-year follow-up after ACLR. Study Design: Cohort study (prognosis); Level of evidence, 1. Methods: Between 2002 and 2008, individuals with ACLR were prospectively enrolled and followed longitudinally using the IKDC, KOOS, and Marx activity score completed at entry, 2, 6, and 10 years. A proportional odds logistic regression model was built incorporating variables from patient characteristics, surgical technique, articular cartilage injuries, and meniscal tears and treatment to determine the predictors (risk factors) of IKDC, KOOS, and Marx outcomes at 10 years. Results: A total of 3273 patients were enrolled (56% male; median age, 23 years at time of enrollment). Ten-year follow-up was obtained on 79% (2575/3273) of the cohort. Incidence of concomitant pathology at the time of surgery consisted of the following: articular cartilage (medial femoral condyle [MFC], 22%; lateral femoral condyle [LFC], 15%; medial tibial plateau [MTP], 4%; lateral tibial plateau [LTP], 11%; patella, 18%; trochlea, 8%) and meniscal pathology (medial, 37%; lateral, 46%). Variables that were predictive of poorer 10-year outcomes included articular cartilage damage in the patellofemoral (P <.01) and medial (P <.05) compartments and previous medial meniscal surgery (7% of knees; P <.04). Compared with no meniscal tear, a meniscal injury was not associated with 10-year outcomes. Medial meniscal repair at the time of ACLR was associated with worse 10-year outcomes for 2 of 5 KOOS subscales, while a medial meniscal repair in knees with grade 2 MFC chondrosis was associated with better outcomes on 2 KOOS subscales. Conclusion: Articular cartilage injury in the patellofemoral and medial compartments at the time of ACLR and a history of medial meniscal surgery before ACLR were associated with poorer 10-year ACLR patient-reported outcomes, but meniscal injury present at the time of ACLR was not. There was limited and conflicting association of medial meniscal repair with these outcomes. [ABSTRACT FROM AUTHOR]

Background: A primary goal of anterior cruciate ligament reconstruction (ACLR) is to reduce pathologically increased anterior and rotational laxity of the knee, but the effects of residual laxity on patient-reported outcomes (PROs) after ACLR remain unclear. Hypothesis: Increased residual laxity at 2 years postoperatively is predictive of a higher risk of subsequent ipsilateral knee surgery and decreases in PRO scores from 2 to 6 years after surgery. Study Design: Cohort study; Level of evidence, 2. Methods: From a prospective multicenter cohort, 433 patients aged <36 years were identified at a minimum 2 years after primary ACLR. These patients underwent a KT-1000 arthrometer assessment and pivot-shift test and completed PRO assessments with the Knee injury and Osteoarthritis Outcome Score and International Knee Documentation Committee (IKDC) scores. Patients completed the same PROs at 6 years postoperatively, and any subsequent ipsilateral knee procedures during this period were recorded. Subsequent surgery risk and change in PROs from 2 to 6 years postoperatively were compared based on residual side-to-side KT-1000 arthrometer differences (<−1 mm, −1 to 2 mm, 2 to 6 mm, and >6 mm) in laxity at 2 years postoperatively. Multiple linear regression models were built to determine the relationship between 2-year postoperative knee laxity and 2- to 6-year change in PROs while controlling for age, sex, body mass index, smoking status, meniscal and cartilage status, and graft type. Results: A total of 381 patients (87.9%) were available for follow-up 6 years postoperatively. There were no significant differences in risk of subsequent knee surgery based on residual knee laxity. Patients with a difference >6 mm in side-to-side anterior laxity at 2 years postoperatively were noted to have a larger decrease in PROs from 2 to 6 years postoperatively (P <.05). No significant differences in any PROs were noted among patients with a difference <6 mm in side-to-side anterior laxity or those with pivot glide (IKDC B) versus no pivot shift (IKDC A). Conclusion: The presence of a residual side-to-side KT-1000 arthrometer difference <6 mm or pivot glide at 2 years after ACLR is not associated with an increased risk of subsequent ipsilateral knee surgery or decreased PROs up to 6 years after ACLR. Conversely, patients exhibiting a difference >6 mm in side-to-side anterior laxity were noted to have significantly decreased PROs at 6 years after ACLR. [ABSTRACT FROM AUTHOR]

Background: The incidence of posttraumatic osteoarthritis (PTOA) based on clinical radiographic grading criteria at 10 years after anterior cruciate ligament (ACL) reconstruction (ACLR) has not been well-defined in a prospective cohort of young athletic patients. Hypothesis: Among young athletic patients, there is a high incidence of clinical radiographic PTOA at 10 years after ACLR. Additionally, there is a significant difference in clinical radiographic osteoarthritis (OA) changes (joint space narrowing and osteophyte formation) between ACL-reconstructed and contralateral knees at 10 years. Study Design: Case series; Level of evidence, 4. Methods: The first 146 patients in an ongoing nested cohort study of the Multicenter Orthopaedic Outcomes Network (MOON) prospective cohort presented for a minimum 10-year follow-up. Included patients had a sports-related ACL injury, were aged <33 years at the time of ACLR, had no history of ipsilateral or contralateral knee surgery, and did not undergo revision ACLR before follow-up. Bilateral knee metatarsophalangeal view radiographs were obtained and graded according to International Knee Documentation Committee (IKDC), Osteoarthritis Research Society International (OARSI), and modified Kellgren-Lawrence (KL) criteria by 2 blinded reviewers. The incidence and severity of ipsilateral and contralateral radiographic OA were determined among patients without a contralateral ACL injury before 10-year follow-up (N = 133). Results: Interrater reliability was substantial for the IKDC (Gwet Agreement Coefficient [AC] 1 = 0.71), moderate for the KL (0.48), and almost perfect for the OARSI (0.84) grading systems. Among patients with a contralateral radiographically normal knee, the 10-year incidence of clinical radiographic PTOA after ACLR was 37% as defined by osteophytes and 23% as defined by joint space narrowing. The maximum side-to-side difference in the OARSI osteophyte grade in the medial or lateral compartment was 0 in 65% of patients, 1 in 20%, and ≥2 in 15%. The maximum side-to-side difference in the OARSI joint space narrowing grade was 0 in 77% of patients, 1 in 19%, and ≥2 in 4%. Conclusion: In young active patients, the 10-year incidence of clinical radiographic PTOA after ACLR was 37% as defined by osteophytes and 23% as defined by joint space narrowing. The mean difference in the degree of osteophyte formation (≤1 grade in 85%) and joint space narrowing (≤1 grade in 96%) between the ACL-reconstructed and contralateral knees was small. Registration: NCT02717559 (ClinicalTrials.gov identifier) [ABSTRACT FROM AUTHOR]

Background: The cause of subsequent surgery after anterior cruciate ligament (ACL) reconstruction varies, but if risk factors for specific subsequent surgical procedures can be identified, we can better understand which patients are at greatest risk. Purpose: To report the incidence and types of subsequent surgery that occurred in a cohort of patients 6 years after their index ACL reconstruction and to identify which variables were associated with the incidence of patients undergoing subsequent surgery after their index ACL reconstruction. Study Design: Cohort study; Level of evidence, 2. Methods: Patients completed a questionnaire before their index ACL surgery and were followed up at 2 and 6 years. Patients were contacted to determine whether any underwent additional surgery since baseline. Operative reports were obtained, and all surgical procedures were categorized and recorded. Logistic regression models were constructed to predict which patient demographic and surgical variables were associated with the incidence of undergoing subsequent surgery after their index ACL reconstruction. Results: The cohort consisted of 3276 patients (56.3% male) with a median age of 23 years. A 6-year follow-up was obtained on 91.5% (2999/3276) with regard to information on the incidence and frequency of subsequent surgery. Overall, 20.4% (612/2999) of the cohort was documented to have undergone at least 1 subsequent surgery on the ipsilateral knee 6 years after their index ACL reconstruction. The most common subsequent surgical procedures were related to the meniscus (11.9%), revision ACL reconstruction (7.5%), loss of motion (7.8%), and articular cartilage (6.7%). Significant risk factors for incurring subsequent meniscus-related surgery were having a medial meniscal repair at the time of index surgery, reconstruction with a hamstring autograft or allograft, higher baseline Marx activity level, younger age, and cessation of smoking. Significant predictors of undergoing subsequent surgery involving articular cartilage were higher body mass index, higher Marx activity level, reconstruction with a hamstring autograft or allograft, meniscal repair at the time of index surgery, or a grade 3/4 articular cartilage abnormality classified at the time of index ACL reconstruction. Risk factors for incurring subsequent surgery for loss of motion were younger age, female sex, low baseline Knee injury and Osteoarthritis Outcome Score symptom subscore, and reconstruction with a soft tissue allograft. Conclusion: These findings can be used to identify patients who are at the greatest risk of incurring subsequent surgery after ACL reconstruction. [ABSTRACT FROM AUTHOR]

Background: Physicians' and patients' decision-making process between bone–patellar tendon–bone (BTB) and hamstring tendon autografts for anterior cruciate ligament (ACL) reconstruction (ACLR) may be influenced by a variety of factors in the young, active athlete. Purpose: To determine the incidence of both ACL graft revisions and contralateral ACL tears resulting in subsequent ACLR in a cohort of high school– and college-aged athletes who initially underwent primary ACLR with either a BTB or a hamstring autograft. Study Design: Cohort study; Level of evidence, 2. Methods: Study inclusion criteria were patients aged 14 to 22 years who were injured in sports, had a contralateral normal knee, and were scheduled to undergo unilateral primary ACLR with either a BTB or a hamstring autograft. All patients were prospectively followed for 6 years to determine whether any subsequent ACLR was performed in either knee after their initial ACLR. Multivariable regression modeling controlled for age, sex, ethnicity/race, body mass index, sport and competition level, baseline activity level, knee laxity, and graft type. The 6-year outcomes were the incidence of subsequent ACLR in either knee. Results: A total of 839 patients were eligible, of which 770 (92%) had 6-year follow-up for the primary outcome measure of the incidence of subsequent ACLR. The median age was 17 years, with 48% female, and the distribution of BTB and hamstring grafts was 492 (64%) and 278 (36%), respectively. The incidence of subsequent ACLR at 6 years was 9.2% in the ipsilateral knee, 11.2% in the contralateral normal knee, and 19.7% for either knee. High-grade preoperative knee laxity (odds ratio [OR], 2.4 [95% confidence interval [CI], 1.4-3.9]; P =.001), autograft type (OR, 2.1 [95% CI, 1.3-3.5]; P =.004), and age (OR, 0.8 [95% CI, 0.7-1.0]; P =.009) were the 3 most influential predictors of ACL graft revision in the ipsilateral knee. The odds of ACL graft revision were 2.1 times higher for patients receiving a hamstring autograft than patients receiving a BTB autograft (95% CI, 1.3-3.5; P =.004). No significant differences were found between autograft choices when looking at the incidence of subsequent ACLR in the contralateral knee. Conclusion: There was a high incidence of both ACL graft revisions and contralateral normal ACL tears resulting in subsequent ACLR in this young athletic cohort. The incidence of ACL graft revision at 6 years after index surgery was 2.1 times higher with a hamstring autograft compared with a BTB autograft. [ABSTRACT FROM AUTHOR]

Background: Understanding the risk factors for loss to follow-up in prospective clinical studies may allow for a targeted approach to minimizing follow-up bias and improving the generalizability of conclusions in anterior cruciate ligament reconstruction (ACLR) and other sports-related interventions. Purpose: To identify independent risk factors associated with failure to complete (ie, loss to follow-up) patient-reported outcome measures (PROMs) at 2 years after ACLR within a well-funded prospective longitudinal cohort. Study Design: Cohort study (prognosis); Level of evidence, 2. Methods: All patients undergoing primary or revision ACLR enrolled in the prospectively collected database of the multicenter consortium between 2002 and 2008 were included. Multivariate regression analyses were conducted to determine which baseline risk factors were significantly associated with loss to follow-up at a minimum of 2 years after surgery. Predictors assessed for loss to follow-up were as follows: consortium site, sex, race, marital status, smoking status, phone number provided (home or cell), email address provided (primary or secondary), years of school completed, average hours worked per week, working status (full-time, part-time, homemaker, retired, student, or disabled), number of people living at home, and preoperative PROMs (Knee injury and Osteoarthritis Outcome Score, Marx Activity Rating Scale, and International Knee Documentation Committee). Results: A total of 3202 patients who underwent ACLR were enrolled. The 2-year PROM follow-up rate for this cohort was 88% (2821 of 3202). Multivariate analyses showed that patient sex (male: odds ratio [OR], 1.80) and race (black: OR, 3.64; other nonwhite: OR, 1.81) were independent predictors of 2-year loss to follow-up of PROMs. Education level was a nonconfounder. Conclusion: While education level did not predict loss to follow-up, patients who are male and nonwhite are at increased risk of loss to follow-up of PROM at 2 years. Capturing patient outcomes with minimal loss depends on equitable, not equal, opportunity to maximize generalizability and mitigate potential population-level health disparities. Registration: NCT00478894 (ClinicalTrials.gov identifier). [ABSTRACT FROM AUTHOR]

Background: While a primary goal of anterior cruciate ligament (ACL) reconstruction is to reduce pathologically increased anterior and rotational knee laxity, the relationship between knee laxity after ACL reconstruction and patient-reported knee function remains unclear. Hypothesis: There would be no significant correlation between the degree of residual anterior and rotational knee laxity and patient-reported outcomes (PROs) 2 years after primary ACL reconstruction. Study Design: Cross-sectional study; Level of evidence, 3. Methods: From a prospective multicenter nested cohort of patients, 433 patients younger than 36 years of age injured in sports with no history of concomitant ligament surgery, revision ACL surgery, or surgery of the contralateral knee were identified and evaluated at a minimum 2 years after primary ACL reconstruction. Each patient underwent Lachman and pivot-shift evaluation as well as a KT-1000 arthrometer assessment along with Knee injury and Osteoarthritis Outcome Score and subjective International Knee Documentation Committee (IKDC) scores. A proportional odds logistic regression model was used to predict each 2-year PRO score, controlling for preoperative score, age, sex, body mass index, smoking, Marx activity score, education, subsequent surgery, meniscal and cartilage status, graft type, and range of motion asymmetry. Measures of knee laxity were independently added to each model to determine correlation with PROs. Results: Side-to-side manual Lachman differences were IKDC A in 246 (57%) patients, IKDC B in 183 (42%) patients, and IKDC C in 4 (<1%) patients. Pivot-shift was classified as IKDC A in 209 (48%) patients, IKDC B in 183 (42%) patients, and IKDC C in 11 (2.5%) patients. The mean side-to-side KT-1000 difference was 2.0 ± 2.6 mm. No significant correlations were noted between pivot-shift or anterior tibial translation as assessed by Lachman or KT-1000 and any PRO. All predicted differences in PROs based on IKDC A versus B pivot-shift and anterior tibial translation were less than 4 points. Conclusion: Neither the presence of IKDC A versus B pivot-shift nor increased anterior tibial translation of up to 6 mm is associated with clinically relevant decreases in PROs 2 years after ACL reconstruction. [ABSTRACT FROM AUTHOR]

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

Background: The time required to develop a secondary cartilage or meniscal injury in the medial compartment after anterior cruciate ligament (ACL) injury is not well understood. Purpose: To determine the association between time delay until ACL reconstruction and the presence of medial compartment Outerbridge grade 3 or 4 chondral injury or medial meniscal tear requiring treatment. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 609 patients underwent primary ACL reconstruction at a single institution at a median 46 days between injury and surgery (61.4% male; mean age, 26.5 years [SD, 11.1]). Chondral status was graded according to Outerbridge criteria at the time of surgery. Multivariate regression analysis was used to assess the relationship between time delay until surgery and medial compartment chondral injury or meniscal injury requiring treatment. Adjustment was performed as needed for patient demographics, sporting activity, and prior knee injuries. Time until surgery had a nonlinear association with medial compartment health and was more effectively described in discrete intervals rather than as a continuous variable. The optimal time intervals to predict medial compartment health were determined by comparison of Bayes information criterion values between fully adjusted regression models. Results: After controlling for relevant confounders, delay of surgery >8 weeks had an increased likelihood of a medial meniscal tear requiring partial meniscectomy (adjusted odds ratio [aOR], 2.30; 95% CI, 1.04-5.12; P = .04) and a decreased likelihood of a meniscal tear requiring repair (aOR, 0.50; 95% CI, 0.32-0.76; P = .001). Delay of surgery >5 months had an increased likelihood of a medial Outerbridge grade ≥3 chondral defect (aOR, 3.11; 95% CI, 1.64-5.87; P = .001) or a grade 4 defect (aOR, 3.84; 95% CI, 1.75-8.45; P = .001). Conclusion: From the time of ACL injury, risk of an irreparable medial meniscal tear found at the time of ACL reconstruction is significantly increased by 8 weeks, and risk of high-grade medial chondral damage is increased by 5 months. [ABSTRACT FROM AUTHOR]

Background: Knee laxity in the setting of anterior cruciate ligament (ACL) injury is often assessed through physical examination using the Lachman, pivot shift, and anterior drawer tests. The degree of laxity noted on these examinations may influence treatment decisions and prognosis. Hypothesis: Increased preoperative knee laxity is associated with increased risk of revision ACL reconstruction, increased risk of contralateral ACL reconstruction, and poorer patient-reported outcomes at 6 years postoperatively. Study Design: Cohort study; Level of evidence, 2. Methods: 2333 patients who underwent primary isolated ACL reconstruction without additional ligament injury were identified. Patients reported by the operating surgeons to have an International Knee Documentation Committee (IKDC) grade D Lachman, anterior drawer, or pivot shift examination were classified as having a high-grade laxity. Multiple logistic regression models were used to evaluate whether having high-grade preoperative laxity was predictive of increased odds of undergoing subsequent revision or contralateral ACL reconstruction within 6 years of the index procedure, controlling for patient age, sex, body mass index, Marx activity level, sport, graft type, medial meniscal treatment, and lateral meniscal treatment. Multiple linear regression modeling was used to evaluate whether having high-grade preoperative laxity was predictive of poorer IKDC or Knee injury and Osteoarthritis Outcome Score Knee-Related Quality of Life (KOOS-QOL) scores at 6 years postoperatively, after controlling for baseline score, patient age, ethnicity, sex, body mass index, marital status, smoking status, sport participation, competition level, Marx activity rating score, graft type, and articular cartilage and meniscal status. Results: In total, 743 of 2325 patients (32.0%) were noted to have high-grade laxity on at least 1 physical examination test. High-grade Lachman was noted in 334 patients (14.4%), high-grade pivot shift was noted in 617 patients (26.5%), and high-grade anterior drawer was noted in 233 patients (10.0%). Six-year revision and contralateral ACL reconstruction data were available for 2129 patients (91.6%). High-grade prereconstruction Lachman was associated with significantly increased odds of ACL graft revision (odds ratio [OR], 1.76; 95% CI, 1.10-2.80, P = .02) and contralateral ACL reconstruction (OR, 1.68; 95% CI, 1.09-2.69; P = .019). High-grade prereconstruction pivot shift was associated with significantly increased odds of ACL graft revision (OR, 1.75; 95% CI, 1.19-2.54, P = .002) but not with significantly increased odds of contralateral ACL reconstruction (OR, 1.30; 95% CI, 0.89-1.87; P = .16). High-grade prereconstruction laxity was associated with statistically significantly lower 6-year IKDC (β = −2.26, P = .003), KOOS-QOL (β = −2.67, P = .015), and Marx activity scores (β = −0.54, P = .020), but these differences did not approach clinically relevant differences in patient-reported outcomes. Conclusion: High-grade preoperative knee laxity is predictive of increased odds of revision ACL reconstruction and contralateral ACL reconstruction 6 years after ACL reconstruction. Poorer patient-reported outcome scores in the high-grade laxity group were also noted, but the difference did not reach a level of clinical relevance. [ABSTRACT FROM AUTHOR]

Background: The Knee injury and Osteoarthritis Outcome Score (KOOS) has demonstrated inferior psychometric properties when compared with the International Knee Documentation Committee (IKDC) subjective knee form when assessing outcomes after anterior cruciate ligament (ACL) reconstruction. The KOOS, Joint Replacement (KOOS, JR) is a validated short-form instrument to assess patient-reported outcomes (PROs) after knee arthroplasty, and the purpose of this study was to determine if augmenting the KOOS, JR with additional KOOS items would allow for the creation of a short-form KOOS-based global knee score for patients undergoing ACL reconstruction, with psychometric properties similar to those of the IKDC. Hypothesis: An augmented version of the KOOS, JR could be created that would demonstrate convergent validity with the IKDC but avoid the ceiling effects and limitations previously noted with several of the KOOS subscales. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Based on preoperative and 2-year postoperative responses to the KOOS questionnaires from a sample of 1904 patients undergoing ACL reconstruction, an aggregate score combining the KOOS, JR and the 4 KOOS Quality of Life subscale questions, termed the KOOSglobal, was developed. Psychometric properties of the KOOSglobal were then compared with those of the IKDC subjective score. Convergent validity between the KOOSglobal and IKDC was assessed with a Spearman correlation (ρ). Responsiveness of the 2 instruments was assessed by calculating the pre- to postoperative effect size and relative efficiency. Finally, the presence of a preoperative floor or postoperative ceiling effect was defined with the threshold of 15% of patients reporting either the worst possible (0 for KOOSglobal and IKDC) or the best possible (100 for KOOSglobal and IKDC) scores, respectively. Results: The newly developed KOOSglobal was responsive after ACL reconstruction and demonstrated convergent validity with the IKDC. The KOOSglobal significantly correlated with the IKDC scores (ρ = 0.91, P < .001), explained 83% of the variability in IKDC scores, and was similarly responsive (relative efficiency = 0.63). While there was a higher rate of perfect postoperative scores with the KOOSglobal (213 of 1904, 11%) than with the IKDC (6%), the KOOSglobal was still below the 15% ceiling effect threshold. Conclusion: The large ceiling effects limit the ability to use several of the KOOS subscales with the younger, more active ACL population. However, by creating an aggregate score from the KOOS, JR and 4 KOOS Quality of Life subscale questions, the 11-item KOOSglobal offers a responsive PRO tool after ACL reconstruction that converges with the information captured with the IKDC. Also, by offering the ability to calculate multiple scores from a single questionnaire, the KOOSglobal may provide the orthopaedic community a single PRO platform to be used across knee-related subspecialties. Registration: NCT00478894 (ClinicalTrials.gov identifier). [ABSTRACT FROM AUTHOR]

Background: Anterior cruciate ligament (ACL) reconstruction can effectively return athletes to the playing field, but they are still at risk of developing posttraumatic osteoarthritis (PTOA). No studies have used multivariable analysis to evaluate the predictors of radiographic PTOA in the lateral compartment of the knee at short-term follow-up after ACL reconstruction. Purpose: To determine the predictors of radiographic joint space narrowing in the lateral compartment 2 to 3 years after ACL reconstruction in a young, active cohort. Study Design: Cohort study; Level of evidence, 2. Methods: A nested cohort of 358 patients from the Multicenter Orthopaedic Outcomes Network (MOON) prospective cohort who were aged ≤33 years, were injured playing a sport, and had never undergone surgery on the contralateral knee were followed up 2 years after ACL reconstruction with questionnaires and with weightbearing knee radiographs using the metatarsophalangeal (MTP) joint technique. The joint space width in the lateral compartment was measured using a semiautomatic computerized method, and multivariable predictive modeling was used to evaluate the relationship between meniscus treatment, cartilage injury, graft type, and joint space while adjusting for age, sex, body mass index, and Marx activity score. Results: The mean lateral joint space width was 0.11 mm narrower on the ACL-reconstructed knee compared with the contralateral healthy knee (7.69 mm vs 7.80 mm, respectively; P < .01). Statistically significant predictors of a narrower joint space width on the ACL-reconstructed knee included lateral meniscectomy (P < .001) and a Marx activity score less than 16 points (P < .001). Conclusion: This study identifies lateral meniscectomy and a lower baseline Marx activity score to be predictors of radiographic joint space narrowing in the lateral compartment 2 to 3 years after ACL reconstruction in young, active patients without a prior knee injury. [ABSTRACT FROM AUTHOR]

Background: The long-term prognosis and risk factors for quality of life and disability after anterior cruciate ligament (ACL) reconstruction remain unknown. Hypothesis/Purpose: Our objective was to identify patient-reported outcomes and patient-specific risk factors from a large prospective cohort at a minimum 10-year follow-up after ACL reconstruction. We hypothesized that meniscus and articular cartilage injuries, revision ACL reconstruction, subsequent knee surgery, and certain demographic characteristics would be significant risk factors for inferior outcomes at 10 years. Study Design: Therapeutic study; Level of evidence, 2. Methods: Unilateral ACL reconstruction procedures were identified and prospectively enrolled between 2002 and 2004 from 7 sites in the Multicenter Orthopaedic Outcomes Network (MOON). Patients preoperatively completed a series of validated outcome instruments, including the International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), and Marx activity rating scale. At the time of surgery, physicians documented all intra-articular abnormalities, treatment, and surgical techniques utilized. Patients were followed at 2, 6, and 10 years postoperatively and asked to complete the same outcome instruments that they completed at baseline. The incidence and details of any subsequent knee surgeries were also obtained. Multivariable regression analysis was used to identify significant predictors of the outcome. Results: A total of 1592 patients were enrolled (57% male; median age, 24 years). Ten-year follow-up was obtained on 83% (n = 1320) of the cohort. Both IKDC and KOOS scores significantly improved at 2 years and were maintained at 6 and 10 years. Conversely, Marx scores dropped markedly over time, from a median score of 12 points at baseline to 9 points at 2 years, 7 points at 6 years, and 6 points at 10 years. The patient-specific risk factors for inferior 10-year outcomes were lower baseline scores; higher body mass index; being a smoker at baseline; having a medial or lateral meniscus procedure performed before index ACL reconstruction; undergoing revision ACL reconstruction; undergoing lateral meniscectomy; grade 3 to 4 articular cartilage lesions in the medial, lateral, or patellofemoral compartments; and undergoing any subsequent ipsilateral knee surgery after index ACL reconstruction. Conclusion: Patients were able to perform sports-related functions and maintain a relatively high knee-related quality of life 10 years after ACL reconstruction, although activity levels significantly declined over time. Multivariable analysis identified several key modifiable risk factors that significantly influence the outcome. [ABSTRACT FROM AUTHOR]

Background: Articular cartilage health is an important issue following anterior cruciate ligament (ACL) injury and primary ACL reconstruction. Factors present at the time of primary ACL reconstruction may influence the subsequent progression of articular cartilage damage. Hypothesis: Larger meniscus resection at primary ACL reconstruction, increased patient age, and increased body mass index (BMI) are associated with increased odds of worsened articular cartilage damage at the time of revision ACL reconstruction. Study Design: Case-control study; Level of evidence, 3. Methods: Subjects who had primary and revision data in the databases of the Multicenter Orthopaedics Outcomes Network (MOON) and Multicenter ACL Revision Study (MARS) were included. Reviewed data included chondral surface status at the time of primary and revision surgery, meniscus status at the time of primary reconstruction, primary reconstruction graft type, time from primary to revision ACL surgery, as well as demographics and Marx activity score at the time of revision. Significant progression of articular cartilage damage was defined in each compartment according to progression on the modified Outerbridge scale (increase ≥1 grade) or >25% enlargement in any area of damage. Logistic regression identified predictors of significant chondral surface change in each compartment from primary to revision surgery. Results: A total of 134 patients were included, with a median age of 19.5 years at revision surgery. Progression of articular cartilage damage was noted in 34 patients (25.4%) in the lateral compartment, 32 (23.9%) in the medial compartment, and 31 (23.1%) in the patellofemoral compartment. For the lateral compartment, patients who had >33% of the lateral meniscus excised at primary reconstruction had 16.9-times greater odds of progression of articular cartilage injury than those with an intact lateral meniscus (P < .001). For the medial compartment, patients who had <33% of the medial meniscus excised at the time of the primary reconstruction had 4.8-times greater odds of progression of articular cartilage injury than those with an intact medial meniscus (P = .02). Odds of significant chondral surface change increased by 5% in the lateral compartment and 6% in the medial compartment for each increased year of age (P ≤ .02). For the patellofemoral compartment, the use of allograft in primary reconstruction was associated with a 15-fold increased odds of progression of articular cartilage damage relative to a patellar tendon autograft (P < .001). Each 1-unit increase in BMI at the time of revision surgery was associated with a 10% increase in the odds of progression of articular cartilage damage (P = .046) in the patellofemoral compartment. Conclusion: Excision of the medial and lateral meniscus at primary ACL reconstruction increases the odds of articular cartilage damage in the corresponding compartment at the time of revision ACL reconstruction. Increased age is a risk factor for deterioration of articular cartilage in both tibiofemoral compartments, while increased BMI and the use of allograft for primary ACL reconstruction are associated with an increased risk of progression in the patellofemoral compartment. [ABSTRACT FROM AUTHOR]

Background: The time between an anterior cruciate ligament (ACL) injury and ACL reconstruction (ACLR) may influence baseline knee-related and general health-related patient-reported outcome measures (PROMs). Despite the common use of PROMs as main outcomes in clinical studies, this variable has never been evaluated. Purpose: To compare baseline health-related quality of life measures and the prevalence/pattern of meniscal and articular cartilage lesions between patients who underwent acute and chronic ACLR so as to provide clinicians with benchmark PROMs in 2 different patient populations with ACL injuries. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 1192 patients from the MOON (Multicenter Orthopaedic Outcomes Network) cohort who underwent primary ACLR were eligible. “Acute” ACLR was defined as <3 months (n = 853; 71.6%) and “chronic” ACLR as >6 months (n = 339; 28.4%) from injury. Patient demographics, surgical characteristics (articular cartilage injury, medial meniscal [MM] and lateral meniscal [LM] tears), and baseline PROM scores (Marx activity rating scale, International Knee Documentation Committee [IKDC] subjective form, Knee injury and Osteoarthritis Outcome Score [KOOS], and Short Form–36 Health Survey [SF-36]) were collected to determine whether the time from injury to ACLR influences (1) baseline PROMs and (2) the pattern and prevalence of concurrent articular cartilage and meniscal injuries. Analysis of covariance models were used to adjust for confounders on baseline outcome scores (age, sex, body mass index [BMI], smoking status, competition level, education). Results: The median patient age was 23 years (interquartile range [IQR], 17-35 years), 530 (44.5%) were female, and the median BMI was 25.0 kg/m2 (IQR, 22.3-27.9 kg/m2); however, the chronic group was older, had a higher BMI, and consisted of fewer collegiate athletes. A significantly greater number of partial LM tears were seen in the acute group versus the chronic group (14.2% vs 6.5%, respectively; P < .001), but there were more meniscal tears overall (73.5% vs 63.2%, respectively; P = .001), complete MM tears (49.0% vs 22.5%, respectively; P < .001), and articular cartilage injuries (54.0% vs 32.8%, respectively; P < .001) in the chronic group versus the acute group. After controlling for confounders, patients in the chronic ACLR group reported a significantly lower baseline Marx score (7.75 vs 12.10, respectively; P < .001) but higher baseline IKDC, SF-36 physical functioning, and all KOOS subscale scores except the KOOS–quality of life subscale score compared to those in the acute ACLR group; however, only the KOOS–sports and recreation subscale exceeded the minimum clinically importance difference of 8 points (62.30 vs 48.26, respectively; P < .001). Conclusion: After controlling for age, sex, competition level, smoking, and BMI, patients in the chronic ACLR group participated in less pivoting and cutting sports but reported better pain/function. Whether decreased activity is deliberate after an ACL injury or patients who undergo chronic ACLR are simply less active and may be treated successfully without surgery warrants further investigation. Nonrandomized studies that utilize PROMs should consider time from injury in study design and data interpretation. [ABSTRACT FROM AUTHOR]

Background: Anterior cruciate ligament reconstruction (ACLR) using a hamstring tendon autograft often results in hamstring muscle strength asymmetry. However, the effect of hamstring muscle strength asymmetry on knee mechanics has not been reported. Hypothesis: Participants with hamstring strength asymmetry would demonstrate altered involved limb knee mechanics during walking and jogging compared with those with more symmetric hamstring strength at least 2 years after ACLR with a hamstring tendon autograft. Study Design: Controlled laboratory study. Methods: There were a total of 45 participants at least 2 years after ACLR (22 male, 23 female; mean time after ACLR, 34.6 months). A limb symmetry index (LSI) was calculated for isometric hamstring strength to subdivide the sample into symmetric hamstring (SH) (LSI ≥90%; n = 18) and asymmetric hamstring (AH) (LSI <85%; n = 18) groups. Involved knee kinematic and kinetic data were collected using 3-dimensional motion analysis during gait and jogging. Peak sagittal-, frontal-, and transverse-plane knee angles and sagittal-plane knee moments and knee powers were calculated. Independent-samples t tests and analyses of covariance were used to compare involved knee kinematic and kinetic variables between the groups. Results: There were no differences in sagittal- and frontal-plane knee angles between the groups (P < .05 for all). The AH group demonstrated decreased tibial internal rotation during weight acceptance during gait (P = .01) and increased tibial external rotation during jogging at initial contact (P = .03) and during weight acceptance (P = .02) compared with the SH group. In addition, the AH group demonstrated decreased peak negative knee power during midstance (P = .01) during gait compared with the SH group, after controlling for gait speed, which differed between groups. Conclusion: Participants with hamstring strength asymmetry showed altered involved knee mechanics in the sagittal plane during gait and in the transverse plane during gait and jogging compared with those with more symmetric hamstring strength. Clinical Relevance: Hamstring strength asymmetry is common at 3 years after ACLR with a hamstring tendon autograft and affects involved knee mechanics during gait and jogging. Additional research is warranted to further investigate the longitudinal effect of these alterations on knee function and joint health after ACLR. [ABSTRACT FROM AUTHOR]

Background: Knee laxity in the setting of suspected anterior cruciate ligament (ACL) injury is frequently assessed through physical examination using the Lachman, pivot-shift, and anterior drawer tests. The degree of laxity noted on these examinations may influence treatment decisions and prognosis. Hypothesis: Increased preoperative knee laxity would be associated with increased risk of subsequent revision ACL reconstruction and worse patient-reported outcomes 2 years postoperatively. Study Design: Cohort study; Level of evidence, 2. Methods: From an ongoing prospective cohort study, 2333 patients who underwent primary isolated ACL reconstruction without collateral or posterior cruciate ligament injury were identified. Patients reported by the operating surgeons as having an International Knee Documentation Committee (IKDC) grade D for Lachman, anterior drawer, or pivot-shift examination were classified as having high-grade laxity. Multiple logistic regression modeling was used to evaluate whether having high-grade preoperative laxity was associated with increased odds of undergoing revision ACL reconstruction within 2 years of the index procedure, controlling for patient age, sex, Marx activity level, level of competition, and graft type. Multiple linear regression modeling was used to evaluate whether having high-grade preoperative laxity was associated with worse IKDC score or Knee injury and Osteoarthritis Outcome Score Knee-Related Quality of Life subscale (KOOS-QOL) scores at a minimum 2 years postoperatively, controlling for baseline score, patient age, ethnicity, sex, body mass index, marital status, smoking status, sport participation, competition level, Marx activity rating score, graft type, and articular cartilage and meniscus status. Results: Pre-reconstruction laxity data were available for 2325 patients (99.7%). Two-year revision data were available for 2259 patients (96.8%), and patient-reported outcomes were available for 1979 patients (84.8%). High-grade preoperative laxity was noted in 743 patients (31.9%). The mean postoperative IKDC score was 81.8 ± 15.9, and the mean KOOS-QOL score was 72.0 ± 22.0. The presence of high-grade pre-reconstruction laxity was associated with significantly increased odds of ACL graft revision (odds ratio [OR] = 1.87 [95% CI, 1.19-2.95]; P = .007). The presence of high-grade pre-reconstruction laxity was not associated with any difference in postoperative IKDC (β = −0.56, P = .44) or KOOS-QOL (β = 0.04, P = .97). Conclusion: The presence of high-grade pre-reconstruction knee laxity as assessed by manual physical examination under anesthesia is associated with significantly increased odds of revision ACL surgery but has no association with patient-reported outcome scores at 2 years after ACL reconstruction. [ABSTRACT FROM AUTHOR]

Background: A patellar dislocation is a common knee injury in the young, athletic patient population. Recent trends indicate that the use of long-term nonoperative treatment is decreasing, and surgical intervention is more commonly recommended for those patients who fail initial nonoperative management with recurrent patellar dislocations. Medial patellofemoral ligament (MPFL) reconstruction has become increasingly utilized in this regard. Purpose: To evaluate outcomes, particularly return to sports and its relationship to postoperative instability, of isolated MPFL reconstruction for the treatment of recurrent patellar dislocations. Study Design: Systematic review and meta-analysis. Methods: A review of the current literature was performed using the terms “medial patellofemoral ligament reconstruction” and “MPFL reconstruction” in the electronic search engines PubMed and EBSCOhost (CINAHL, MEDLINE, SPORTDiscus) on July 29, 2015, yielding 1113 abstracts for review. At the conclusion of the search, 14 articles met the inclusion criteria and were included in this review of the literature. Means were calculated for population size, age, follow-up time, and postoperative Tegner scores. Pooled estimates were calculated for postoperative Kujala scores, return to play, total risk of postoperative instability, risk of positive apprehension sign, and risk of reoperation. Results: The mean patient age associated with MPFL reconstruction was 24.4 years, with a mean postoperative Tegner score of 5.7. The pooled estimated mean postoperative Kujala score was 85.8 (95% CI, 81.6-90.0), with 84.1% (95% CI, 71.1%-97.1%) of patients returning to sports after surgery. The pooled total risk of recurrent instability after surgery was 1.2% (95% CI, 0.3%-2.1%), with a positive apprehension sign risk of 3.6% (95% CI, 0%-7.2%) and a reoperation risk of 3.1% (95% CI, 1.1%-5.0%). Conclusion: A high percentage of young patients return to sports after isolated MPFL reconstruction for chronic patellar instability, with short-term results demonstrating a low incidence of recurrent instability, postoperative apprehension, and reoperations. [ABSTRACT FROM AUTHOR]

Background: American football and rugby players are at substantial risk of injury because of the full-contact nature of these sports. Methodological differences between previous epidemiological studies hamper an accurate comparison of injury rates between American football and rugby. Purpose: To directly compare injury rates in American collegiate football and rugby, specified by location, type, mechanism, and severity of injury, as reported by licensed medical professionals. Study Design: Cohort study; Level of evidence, 2. Methods: Licensed medical professionals (athletic trainer or physician) associated with the football and rugby teams of a National Collegiate Athletic Association Division I university reported attendance and injury details over 3 autumn seasons. Injuries were categorized by the location, type, mechanism, and severity of injury, and the injury rate was calculated per 1000 athlete-exposures (AEs). Injury rate ratios (IRRs) were calculated to compare overall, game, and practice injury rates within and between sports. Results: The overall injury rate was 4.9/1000 AEs in football versus 15.2/1000 AEs in rugby: IRR = 3.1 (95% CI, 2.3-4.2). Game injury rates were higher than practice injury rates: IRR = 6.5 (95% CI, 4.5-9.3) in football and IRR = 5.1 (95% CI, 3.0-8.6) in rugby. Injury rates for the shoulder, wrist/hand, and lower leg and for sprains, fractures, and contusions in rugby were >4 times as high as those in football (all P ≤ 0.006). Concussion rates were 1.0/1000 AEs in football versus 2.5/1000 AEs in rugby. Most injuries occurred via direct player contact, especially during games. The rate of season-ending injuries (>3 months of time loss) was 0.8/1000 AEs in football versus 1.0/1000 AEs in rugby: IRR = 1.3 (95% CI, 0.4-3.4). Conclusion: Overall injury rates were substantially higher in collegiate rugby compared with football. Similarities between sports were observed in the most common injury types (sprains and concussions), locations (lower extremity and head), and mechanisms (direct player contact). Upper extremity injuries were more common in rugby, and the rate of season-ending injuries was similar between sports. [ABSTRACT FROM AUTHOR]

Unlabelled: Nonunion, delayed union, and refracture after operative treatment of acute proximal fifth metatarsal fractures in athletes is uncommon. This study was a failure analysis of operatively managed acute proximal fifth metatarsal fractures in healthy athletes. We identified 149 patients who underwent operative treatment for fifth metatarsal fractures. Inclusion criteria isolated skeletally mature, athletic patients under the age of 40 with a minimum of 1-year follow-up. Patients were excluded with tuberosity fractures, fractures distal to the proximal metaphyseal-diaphyseal region of the fifth metatarsal, multiple fractures or operative procedures, fractures initially treated conservatively, and medical comorbidities/risk factors for nonunion. Fifty-five patients met the inclusion/exclusion criteria. Four (7.3%) patients required a secondary operative procedure due to refracture. The average time to refracture was 8 months. All refractures were associated with bent screws and occurred in male patients who participated in professional basketball, professional volleyball, and college football. The average time for release to progressive weight-bearing was 6 weeks. Three patients were revised to a bigger size screw and went on to union. One patient was revised to the same-sized screw and required a second revision surgery for nonunion. All failures were refractures in competitive athletes who were initially treated with small diameter solid or cannulated stainless steel screws. The failures were not associated with early postoperative weight-bearing protocol. Maximizing initial fixation stiffness may decrease the late failure rate in competitive athletes. More clinical studies are needed to better understand risk factors for failure after screw fixation in the competitive, athletic population.Level Of Evidence: Prognostic, Level IV: Case series. [ABSTRACT FROM AUTHOR]

Background: The management of meniscus tears identified at the time of primary anterior cruciate ligament (ACL) reconstruction is highly variable and includes repair, meniscectomy, and nontreatment. Hypothesis/Purpose: The purpose of this study was to determine the reoperation rate for meniscus tears left untreated at the time of ACL reconstruction with a minimum follow-up of 6 years. The hypothesis was that small peripheral tears identified at the time of ACL reconstruction managed with “no treatment” would have successful clinical outcomes. Study Design: Cohort study; Level of evidence, 3. Methods: Patients with meniscus tears left untreated at the time of primary ACL reconstruction were identified from a multicenter study group with a minimum 6-year follow-up. Patient, tear, and reoperation data were obtained for analysis. The need for reoperation was used as the primary endpoint, with analysis performed to determine patient and tear characteristics associated with reoperation. Results: There were 194 patients with 208 meniscus tears (71 medial, 137 lateral) left in situ without treatment with a complete follow-up for analysis. Of these, 97.8% of lateral and 94.4% of medial untreated tears required no reoperation. Sixteen tears (7.7%) left in situ without treatment underwent subsequent reoperation: 9 tears (4.3%) underwent reoperation in the setting of revision ACL reconstruction, and 7 tears (3.4%) underwent reoperation for an isolated meniscus injury. The patient age was significantly lower in patients requiring reoperation, while tears measuring ≥10 mm more frequently required reoperation. Conclusion: Lateral and medial meniscus tears left in situ at the time of ACL reconstruction did not require reoperation at a minimum 6-year follow-up for 97.8% and 94.4% of tears, respectively. These findings re-emphasize the low reoperation rate after the nontreatment of small, peripheral lateral meniscus tears while noting less predictable results for medial meniscus tears left without treatment. [ABSTRACT FROM AUTHOR]

Background: Anterior cruciate ligament (ACL) reinjury results in worse outcomes and increases the risk of posttraumatic osteoarthritis. Purpose: To identify the risk factors for both ipsilateral and contralateral ACL tears after primary ACL reconstruction (ACLR). Study Design: Cohort study; Level of evidence, 3. Methods: Data from the Multicenter Orthopaedic Outcomes Network (MOON), a prospective longitudinal cohort, were used to identify risk factors for ACL retear. Subjects with primary ACLR, no history of contralateral knee surgery, and a minimum of 2-year follow-up data were included. Age, sex, Marx activity score, graft type, lateral meniscal tear, medial meniscal tear, sport played at index injury, and surgical facility were evaluated to determine their contribution to both ipsilateral retear and contralateral ACL tear. Results: A total of 2683 subjects with average age of 27 ± 11 years (1498 men; 56%) met all study inclusion/exclusion criteria. Overall there were 4.4% ipsilateral graft tears and 3.5% contralateral ACL tears. The odds of ipsilateral ACL retear were 5.2 times greater for an allograft (P < .01) compared with a bone-patellar tendon-bone (BTB) autograft; the odds of retear were not significantly different between BTB autograft and hamstring autograft (P = .12). The odds of an ipsilateral ACL retear decreased by 0.09 for every yearly increase in age (P < .01) and increased by 0.11 for every increased point on the Marx score (P < .01). These odds were not significantly influenced by sex, smoking status, sport played, medial or lateral meniscal tear, or consortium site (P > .05). The odds of a contralateral ACL tear decreased by 0.04 for every yearly increase in age (P = .04) and increased by 0.12 for every increased point on the Marx score (P < .01); these odds were not significantly different between sex, smoking status, sport played, graft type, medial meniscal tear, or lateral meniscal tear (P > .05). Conclusion: Younger age, higher activity level, and allograft graft type were predictors of increased odds of ipsilateral graft failure. Higher activity and younger age were found to be risk factors in contralateral ACL tears. [ABSTRACT FROM AUTHOR]

The article discusses the literature review for the treatment and outcomes of medial malleolar stress fractures in athletes between operative and nonoperative treatment. Topics discussed include the extraction of data, factors which affects the decision on operative versus nonoperative treatment, and the results which states that nonoperative and operative treatment were proven to be successful for the treatment.

The article discusses a study on the ability of meniscus tears and articular cartilage lesions to predict Knee injury and Osteoarthritis Outcome Scores (KOOS), Marx Activity Level outcomes and International Knee Documentation Committee (IKDC) score after anterior cruciate ligament reconstruction (ACLR). Conducted was a regression model for variables including surgical technique, meniscus tears (MT) and articular cartilage injury (ACI). Conclusions indicated MT and ACI as predictors of IKDC.

The article provides a systematic review of autograft and nonirradiated allograft tissue for anterior cruciate ligament reconstruction (ACLR). The review included nine studies and determined whether the use of nonirradiated allograft tissue is linked with poorer outcomes when compared with autografts. The researchers found no significant differences in graft failure rate, postoperative laxity, or patient-reported outcome scores in the systematic review.

Background: In vivo studies reporting tibial plateau slope as a risk factor for anterior cruciate ligament (ACL) injury have been published with greatly increasing frequency. Purpose: To examine and summarize the in vivo evidence comparing tibial slope in ACL-injured and uninjured populations. Study Design: Systematic review and meta-analysis. Methods: We reviewed publications in Scopus, SPORTDiscus, CINAHL, and PubMed to identify all studies reporting a measure of tibial plateau slope between ACL-injured groups and controls. A meta-analysis was performed including calculation of effect size and 95% confidence interval as well as 95% confidence intervals for the mean values of the measurement in each study. Results: Fourteen studies met our inclusion/exclusion criteria. Five of 6 radiographic studies reporting medial tibial plateau slope (MTPS) demonstrated significant differences between controls and ACL-injured groups, while only 1 of 7 magnetic resonance imaging (MRI) studies reported significant differences between groups. Mean MTPS measurements and standard deviations reported for controls ranged from 2.9° ± 2.8° anterior to 9.5° ± 3° posterior. For ACL-injured patients, MTPS ranged from 1.8° ± 3.5° anterior to 12.1° ± 3.3° posterior. Lateral tibial plateau slope (LTPS) was reported to be significantly greater in ACL-injured groups in all 5 MRI-based studies reporting group comparisons. Mean values for LTPS in controls ranged from 0.3° ± 3.6° anterior slope to 9° ± 4° posterior slope. In ACL-injured groups, mean reported LTPS values ranged from 1.8° ± 3.2° to 11.5° ± 3.54° posterior slope. Conclusion: Despite high measures of reliability for the various methods reported in current studies, there is vast disagreement regarding the actual values of the slope that would be considered ‘‘at risk.’’ Reported tibial slope values for control groups vary greatly between studies. In many cases, the study-to-study differences in ‘‘normal’’ tibial slope exceed the difference between controls and ACL-injured patients. The clinical utility of imaging-based measurement methods for the determination of ACL injury risk requires more reliable techniques that demonstrate consistency between studies. [ABSTRACT FROM AUTHOR]

Background: At the time of anterior cruciate ligament (ACL) reconstruction, there are usually concurrent meniscal and articular cartilage injuries. It is unclear if there is a significant difference between intra-articular injuries at the time of a primary ACL reconstruction compared with revision ACL reconstruction.Purpose: To compare the meniscal and articular cartilage injuries found at the time of primary and revision ACL reconstruction surgery and to determine associations between primary and revision surgery and specific intra-articular findings.Study Design: Cohort study (prevalence); Level of evidence, 2.Methods: Primary and revision ACL surgeries were identified from the Multicenter Orthopedic Outcomes Network (MOON) and Multicenter ACL Revision Study (MARS) study groups, respectively, from January 1, 2007 to November 1, 2008. Demographic data on individual patients were analyzed including age, body mass index (BMI), and gender. Intra-articular findings including the presence of medial or lateral meniscal tears and chondral damage to articular surfaces were analyzed for each patient. Comparisons of intra-articular findings at the time of surgery for the 2 groups were analyzed. Chondral damage in the medial and lateral compartments was analyzed considering previous meniscal tear as a possible confounder.Results: There were 508 patients undergoing primary ACL reconstruction and 281 patients undergoing revision ACL reconstruction who were identified for inclusion. There were no differences in the mean age, BMI, and gender in the 2 study groups. There was a decreased odds ratio (OR) of new untreated lateral meniscal tears (OR, 0.54; P < .01) but not of medial meniscal tears (OR, 0.86; P = .39) in revision compared with primary ACL reconstruction. There was an increased OR of Outerbridge grade 3 and 4 articular cartilage injury in revision compared with primary ACL reconstruction in the lateral compartment (OR, 1.73; P = .04) and in the patellar-trochlear compartment (OR, 1.70; P = .04) but not in the medial compartment (OR, 1.33; P = .23). There was an increased OR of Outerbridge grade 3 and 4 articular cartilage injury in patients from both groups having a prior medial meniscectomy on the medial femoral condyle (OR, 1.44; P < .01) and on the medial tibial plateau (OR, 1.63; P < .01). There was an increased OR of Outerbridge grade 3 and 4 articular cartilage injury in patients from both groups having a prior lateral meniscectomy on the lateral femoral condyle (OR, 1.65; P < .01) and on the lateral tibial plateau (OR, 1.56; P < .01).Conclusion: Meniscal tears are a common finding in both primary and revision ACL reconstruction. These results show a decreased OR of new untreated lateral meniscal tears in revision compared with primary ACL reconstruction. A previous medial or lateral meniscectomy increases the OR of articular cartilage damage in the medial or lateral compartments, respectively. Even when controlling for meniscus status, there is an increased OR in revision compared with primary ACL reconstruction of significant lateral compartment and patellar-trochlear chondral damage but not medial compartment chondral damage. [ABSTRACT FROM AUTHOR]

Background: The predictors of anterior cruciate ligament reconstruction (ACLR) outcome at 6 years as measured by validated patient-based outcome instruments are unknown.Hypothesis: Certain variables evaluated at the time of ACLR will predict return to sports function (as measured by the International Knee Documentation Committee [IKDC] questionnaire and the Knee injury and Osteoarthritis Outcome Score [KOOS] Sports and Recreation subscale), knee-related quality of life (KOOS Knee Related Quality of Life subscale), and activity level (Marx Activity Scale). Potential predictor variables include demographic factors, surgical technique and graft choice for ACLR, and intra-articular injuries and treatment.Study Design: Cohort study; Level of evidence, 2.Methods: All patients with unilateral ACLRs from 2002 currently enrolled in the MOON (Multicenter Orthopaedic Outcomes Network) cohort were evaluated. Patients completed the validated outcome instruments preoperatively. Physicians documented intra-articular pathologic abnormalities, treatment, and surgical techniques used at the time of surgery. At 2 and 6 years postoperatively, patients completed the same validated outcome instruments.Results: Follow-up was obtained at 2 years (88%) and at 6 years (84%). The cohort was 57% male with a median age of 23 years at enrollment. The ability to perform sports function was maintained at 6 years, but the Marx activity level continued to decline from baseline. Revision ACLR and use of allograft predicted worse outcomes on the IKDC and both KOOS subscales. Lateral meniscus treatment, smoking status, and body mass index at baseline were each predictors on 2 of 3 scales. The predictors of lower activity level were revision ACLR and female sex.Conclusion: Six years after ACLR, patients could perform sports-related functions and maintain a high knee-related quality of life similar to their 2-year level, although their physical activity level (Marx) dropped over time. Choosing autograft rather than allograft, not smoking, and having normal body mass index are advised to improve long-term outcomes. [ABSTRACT FROM AUTHOR]

Background: Tearing an anterior cruciate ligament (ACL) graft is a devastating occurrence after ACL reconstruction (ACLR). Identifying and understanding the independent predictors of ACLR graft failure is important for surgical planning, patient counseling, and efforts to decrease the risk of graft failure.Hypothesis: Patient and surgical variables will predict graft failure after ACLR.Study Design: Prospective cohort study.Methods: A multicenter group initiated a cohort study in 2002 to identify predictors of ACLR outcomes, including graft failure. First, to control for confounders, a single surgeon's data (n = 281 ACLRs) were used to develop a multivariable regression model for ACLR graft failure. Evaluated variables were graft type (autograft vs allograft), sex, age, body mass index, activity at index injury, presence of a meniscus tear, and primary versus revision reconstruction. Second, the model was validated with the rest of the multicenter study's data (n = 645 ACLRs) to evaluate the generalizability of the model.Results: Patient age and ACL graft type were significant predictors of graft failure for all study surgeons. Patients in the age group of 10 to 19 years had the highest percentage of graft failures. The odds of graft rupture with an allograft reconstruction are 4 times higher than those of autograft reconstructions. For each 10-year decrease in age, the odds of graft rupture increase 2.3 times.Conclusion: There is an increased risk of ACL graft rupture in patients who have undergone allograft reconstruction. Younger patients also have an increased risk of ACL graft failure.Clinical Relevance: Given these risks for ACL graft rupture, allograft ACLRs should be performed with caution in the younger patient population. [ABSTRACT FROM AUTHOR]

Background: Increased knee pain at the time of anterior cruciate ligament reconstruction may potentially predict more difficult rehabilitation, prolonged recovery, and/or be predictive of increased knee pain at 2 years.Hypothesis: A bone bruise and/or other preoperative factors are associated with more knee pain/symptoms at the time of index anterior cruciate ligament reconstruction, and the presence of a bone bruise would be associated with specific demographic and injury-related factors.Study Design: Cohort study (prevalence); Level of evidence, 2.Methods: In 2007, the Multicenter Orthopaedic Outcomes Network (MOON) database began to prospectively collect surgeon-reported magnetic resonance imaging bone bruise status. A multivariable analysis was performed to (1) determine if a bone bruise, among other preoperative factors, is associated with more knee symptoms/pain and (2) examine the association of factors related to bone bruise. To evaluate the association of a bone bruise with knee pain/symptoms, linear multiple regression models were fit using the continuous scores of the Knee injury and Osteoarthritis Outcome Score (KOOS) symptoms and pain subscales and the Short Form 36 (SF-36) bodily pain subscale as dependent variables. To examine the association between a bone bruise and risk factors, a logistic regression model was used, in which the dependent variable was the presence or absence of a bone bruise.Results: Baseline data for 525 patients were used for analysis, and a bone bruise was present in 419 (80%). The cohort comprises 58% male patients, with a median age of 23 years. The median Marx activity level was 13. Factors associated with more pain were higher body mass index (P < .0001), female sex (P = .001), lateral collateral ligament injury (P = .012), and older age (P = .038). Factors associated with more symptoms were a concomitant lateral collateral ligament injury (P = .014), higher body mass index (P < .0001), and female sex (P < .0001). Bone bruise is not associated with symptoms/pain at the time of index anterior cruciate ligament reconstruction. None of the factors included in the SF-36 bodily pain model were found to be significant. After controlling for other baseline factors, the following factors were associated with a bone bruise: younger age (P = .034) and not jumping at the time of injury (P = .006).Conclusion: After anterior cruciate ligament injury, risk factors associated with a bone bruise are younger age and not jumping at the time of injury. Bone bruise is not associated with symptoms/pain at the time of index anterior cruciate ligament reconstruction. [ABSTRACT FROM PUBLISHER]

Background: Very few studies examining the predisposing anatomical factors leading to anterior cruciate ligament (ACL) injuries have examined the ACL itself, and none of these directly examined the difference in ACL properties between injured and matched control subjects. Hypothesis: The ACL total volume in people who have experienced a noncontact ACL injury is smaller than that of matched controls. Study Design: Case control study; Level of evidence, 3. Methods: Contours of the ACL were manually identified in sagittal magnetic resonance images, and volumes were calculated for 27 contralateral, healthy knees of individuals after noncontact ACL injury and for 27 control subjects matched for gender, height, age, and weight. Validation of this method was performed on 5 porcine knees. Stepwise multiple regression was used to determine the difference in ACL volume between injured and control subjects while considering gender, height, weight, and age as potential covariates. Results: Contralateral ACL volume for injured subjects was significantly smaller than for noninjured subjects (P = .0208) by 231 mm3 after adjusting for weight, which was also a significant contributor to ACL volume (P < .0001). At the average body mass of 72.7 kg, subjects with a noncontact ACL injury had an average contralateral ACL volume of 1921 mm3, while the corresponding control group had an average volume of 2151 mm3. Gender, height, and age were not significant when weight was included in the regression model. Conclusion: This study shows that there are anthropometric differences between the knees of subjects with a noncontact ACL injury and those without an ACL injury, suggesting that ACL volume may play a direct role in noncontact ACL injury. [ABSTRACT FROM AUTHOR]

Background: Meniscal repair is performed in an attempt to prevent posttraumatic arthritis resulting from meniscal dysfunction after meniscal tears. The socioeconomic implications of premature arthritis are significant in the young patient population. Investigations and techniques focusing on meniscus preservation and healing are now at the forefront of orthopaedic sports medicine. Hypothesis: Concomitant meniscal repair with anterior cruciate ligament reconstruction is a durable and successful procedure at 2-year follow-up. Study Design: Case series; Level of evidence, 4. Methods: All unilateral primary anterior cruciate ligament reconstructions entered in 2002 in a cohort who had meniscal repair at the time of anterior cruciate ligament reconstruction were evaluated. Validated patient-oriented outcome instruments were completed preoperatively and then again at the 2-year postoperative time point. Reoperation after the index procedure was also documented and confirmed by operative reports. Results: A total of 437 unilateral primary anterior cruciate ligament reconstructions were performed with 82 concomitant meniscal repairs (54 medial, 28 lateral) in 80 patients during the study period. Patient follow-up was obtained on 94% (77 of 82) of the meniscal repairs, allowing confirmation of meniscal repair success (defined as no repeat arthroscopic procedure) or failure. The overall success rate for meniscal repairs was 96% (74 of 77 patients) at 2-year follow-up. Conclusion: Meniscal repair is a successful procedure in conjunction with anterior cruciate ligament reconstruction. When confronted with a "repairable" meniscal tear at the time of anterior cruciate ligament reconstruction, orthopaedic surgeons can expect an estimated >90% clinical success rate at 2-year follow-up using a variety of methods as shown in our study. [ABSTRACT FROM AUTHOR]

Background: The 1-incision and 2-incision techniques are commonly used methods to repair a distal biceps rupture, and they differ in the location of reinsertion of tendon into bone. Hypothesis: The native distal biceps brachii tendon inserts on the posterior-ulnar aspect of the bicipital tuberosity, which functions as a cam, increasing the tendon's moment arm during its principal action of forearm supination. Repair of the distal biceps tendon to the anterior aspect of the tuberosity compromises forearm supination due to absence of the bicipital tuberosity's cam effect. Study Design: Controlled laboratory study. Methods: Eleven matched pairs of fresh-frozen cadaveric upper extremities were prepared for repair of the distal biceps tendon using either anterior or posterior reattachment with transosseous suture fixation. Specimens were tested on a materials testing machine with intact distal biceps insertion and after repair. A load cell at the distal radial-ulnar joint measured resultant elbow flexion and forearm supination torque produced by 100-N force applied to the proximal aspect of the tendon. Results: Although there was a trend (P = .104) toward loss of supination torque with the anterior reconstruction method, no significant differences in torque (0.80 vs 0.89 Nm) or flexion force (11.87 vs 12.07 N) were found between the anterior and posterior reconstruction techniques. Conclusion: There is no statistically significant difference in flexion force or supination torque between the anterior and posterior reconstruction techniques. Clinical Relevance: This study supports existing limited clinical data suggesting no functional differences exist between 2 common repair methods. Further biomechanical and clinical investigations directly comparing the results of distal biceps tendon repairs made to the anterior aspect versus the posterior aspect of the tuberosity are necessary to definitely determine if differences exist in resultant elbow flexion and forearm supination functions. [ABSTRACT FROM AUTHOR]

Background: The risk of tear of the intact anterior cruciate ligament in the contralateral knee after anterior cruciate ligament reconstruction of the opposite knee and the incidence of rupturing the anterior cruciate ligament graft during the first 2 years after surgery have not been extensively studied in a prospective manner. Clinicians have hypothesized that the opposite normal knee is at equal or increased risk compared with the risk of anterior cruciate ligament graft rupture in the operated knee. Hypothesis: The risk of anterior cruciate ligament graft rupture and contralateral normal knee anterior cruciate ligament rupture at 2-year follow-up is equal. Study Design: Cohort study; Level of evidence, 2. Methods: The Multicenter Orthopaedic Outcome Network (MOON) database of a prospective longitudinal cohort of anterior cruciate ligament reconstructions was used to determine the number of anterior cruciate ligament graft ruptures and tears of the intact anterior cruciate ligament in the contralateral knee at 2-year follow-up. Two-year follow-up consisted of a phone interview and review of operative reports. Results: Two-year data were obtained for 235 of 273 patients (86%). There were 14 ligament disruptions. Of these, 7 were tears of the intact anterior cruciate ligament in the contralateral knee (3.0%) and 7 were anterior cruciate ligament graft failures (3.0%). Conclusion: The contralateral normal knee anterior cruciate ligament is at a similar risk of anterior cruciate ligament tear (3.0%) as the anterior cruciate ligament graft after primary anterior cruciate ligament reconstruction (3.0%). [ABSTRACT FROM AUTHOR]

Focuses on a study which examined the effects of radiofrequency energy treatment on chondrocytes and matrix of fibrillated articular cartilage. Experimental design; Analysis of proteoglycan synthesis and degradation; Conclusion.

Reports on magnetic resonance imaging findings and the results of surgical treatment and histologic evaluation of athletes with recalcitrant patellar tendinitis. Study subjects and methods of treatment; Surgical exploration and debridement on the knees; Histological findings and magnetic resonance findings of the surgical treatment.

Background: Pain and injuries suffered by youth pitchers are ongoing concerns that have been addressed through the institution of rules and recommendations regarding pitch counts and rest periods. The aim of our study was to see if coaches of youth baseball pitchers in our region were aware of the recommended guidelines and if they followed them.Methods: An Internet-based survey consisting of 18 items including demographic information and questions concerning the USA Baseball Medical and Safety Advisory Committee pitching guidelines was sent to coaches affiliated with a local youth league to assess their knowledge of and reported compliance with these recommendations.Results: Ninety-five of 228 coaches (41.4%) participated in the survey. On average, coaches answered 43% of questions regarding pitch count and rest periods correctly; 73% reported that they followed the recommendations, while only 53% felt that other coaches in the league abided by the recommendations. Thirty-five percent of coaches stated that their pitchers reported shoulder or elbow pain during the season, and 19% reported that one of their pitchers pitched a game with a sore or fatigued arm during the season. No coaches reported any pitching-related injuries among their players requiring surgery. Fewer than 10% of coaches reported that their players pitched in multiple leagues or participated in showcases, while 91% reported that pitchers attended camps or received specific instruction to improve their pitching form.Conclusions: This study shows that this subset of youth baseball coaches is deficient with regard to knowledge of the USA Baseball Medical and Safety Advisory Committee pitching guidelines. This situation may put youth pitchers at increased risk for upper extremity pain and injuries. [ABSTRACT FROM AUTHOR]