Adolescent patellar osteochondral fracture following patellar dislocation.

PURPOSE: Patellar dislocations in adolescents may cause osteochondral fractures of the patella. The aim of this study was to review the outcomes of adolescent patients who underwent surgical intervention for patellar osteochondral fracture following patellar dislocation. METHODS: Nine patients who underwent surgery for osteochondral fracture of the patella following dislocation were identified retrospectively. Following arthroscopic examination, if the fragment was large enough to support fixation, headless screws or bioabsorbable pins were used. Otherwise, the loose body was excised, and the donor site was managed with a microfracture. Postoperatively, patients were assessed using the International Knee Documentation Committee (IKDC) and Knee injury and Osteoarthritis Outcome Score (KOOS) outcome measures. RESULTS: The average age of the patients was 14.6 with average follow-up 30.2 months. Four of the nine patients underwent fixation, while five patients underwent removal of loose body with microfracture. The average defect size in the nonfixation group was 1.2 cm(2) compared with 3.2 cm(2) in the fixation group. The IKDC scores for fixation and nonfixation groups were 63.9 (SD = 18) and 76.1 (SD = 11.7), respectively. The KOOS subscale scores for symptoms, function in sports and recreation, and knee-related quality of life were higher for the nonfixation group when compared to the fixation group. CONCLUSIONS: This is the first known series examining surgical outcomes of osteochondral fractures of the patella following patellar dislocations in the adolescent population. While patients without fixation were less symptomatic in this series, this may be attributable to more severe injuries in patients undergoing fracture fixation. LEVEL OF EVIDENCE: Retrospective case series, Level IV.

Cadaveric Analysis of Key Anatomic Structures of Athletic Pubalgia.

PURPOSE: This study proposes to establish in-depth inspection of the anatomic structures involved with the pathology of athletic pubalgia in a cadaver model. METHODS: Eight male fresh frozen cadavers were dissected in a layered fashion. The rectus abdominis (RA) and adductor longus (AL) tendon insertions were isolated to quantify the size of the anatomic footprint and distance from the surrounding anatomy. RESULTS: The RA insertional footprint was 1.65 cm (SD, 0.18) in width by 1.02 cm (SD, 0.26) in length, and the AL insertional footprint on the underside of the pubis was 1.95 cm (SD, 0.28) in length by 1.23 cm (SD, 0.33) in width. The ilioinguinal nerve was 2.49 cm (SD, 0.36) lateral to the center of the RA footprint and 2.01 cm (SD, 0.37) lateral to the center of the AL footprint. The spermatic cord and the genitofemoral nerve were just lateral to the ilioinguinal nerve and were 2.76 cm (SD, 0.44) and 2.66 cm (SD, 0.46) from the rectus and AL footprints, respectively. CONCLUSION: Surgeons should be cognizant of these anatomic relations during both initial dissection and tendon repair to optimize repair and avoid iatrogenic injury to critical structures in the anterior pelvis.

Preoperative Risk Factors for Subsequent Ipsilateral ACL Revision Surgery After an ACL Restoration Procedure.

BACKGROUND: Anterior cruciate ligament (ACL) revision surgery is challenging for both patients and surgeons. Understanding the risk factors for failure after bridge-enhanced ACL restoration (BEAR) may help with patient selection for ACL restoration versus ACL reconstruction. PURPOSE: To identify the preoperative risk factors for ACL revision surgery within the first 2 years after BEAR. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Data from the prospective BEAR I, II, and III trials were used to determine the preoperative risk factors for ACL revision surgery. All patients with a complete ACL tear (aged 13-47 years, depending on the trial), who met all other inclusion/exclusion criteria and underwent a primary BEAR procedure within 30 to 50 days from the injury (dependent on the trial), were included. Demographic data (age, sex, body mass index), baseline patient-reported outcomes (International Knee Documentation Committee [IKDC] subjective score, Marx activity score), preoperative imaging results (ACL stump length, notch size, tibial slope), and intraoperative findings (knee hyperextension, meniscal status) were evaluated to determine their contribution to the risk of ipsilateral ACL revision surgery. RESULTS: A total of 123 patients, with a median age of 17.6 years (interquartile range, 16-23 years), including 67 (54%) female patients, met study criteria. Overall, 18 (15%) patients required ACL revision surgery in the first 2 years after the BEAR procedure. On bivariate analyses, younger age (P = .011), having a contact injury at the time of the initial tear (P = .048), and increased medial tibial slope (MTS; P = .029) were associated with a higher risk of ipsilateral revision surgery. Multivariable logistic regression analyses identified 2 independent predictors of revision: patient age and MTS. The odds of ipsilateral revision surgery were decreased by 32% for each 1-year increase in age (odds ratio, 0.684 [95% CI, 0.517-0.905]; P = .008) and increased by 28% for each 1° increase in MTS (odds ratio, 1.280 [95% CI, 1.024-1.601]; P = .030). Sex, baseline IKDC or Marx score, knee hyperextension, and meniscal status were not significant predictors of revision. CONCLUSION: Younger age and higher MTS were predictors of ipsilateral ACL revision surgery after the BEAR procedure. Younger patients with higher tibial slopes should be aware of the increased risk for revision surgery when deciding to undergo ACL restoration.

Quantitative MRI Biomarkers to Predict Risk of Reinjury Within 2 Years After Bridge-Enhanced ACL Restoration.

BACKGROUND: Quantitative magnetic resonance imaging (qMRI) methods were developed to establish the integrity of healing anterior cruciate ligaments (ACLs) and grafts. Whether qMRI variables predict risk of reinjury is unknown. PURPOSE: To determine if qMRI measures at 6 to 9 months after bridge-enhanced ACL restoration (BEAR) can predict the risk of revision surgery within 2 years of the index procedure. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Originally, 124 patients underwent ACL restoration as part of the BEAR I, BEAR II, and BEAR III prospective trials and had consented to undergo an MRI of the surgical knee 6 to 9 months after surgery. Only 1 participant was lost to follow-up, and 4 did not undergo MRI, leaving a total of 119 patients for this study. qMRI techniques were used to determine the mean cross-sectional area; normalized signal intensity; and a qMRI-based predicted failure load, which was calculated using a prespecified equation based on cross-sectional area and normalized signal intensity. Patient-reported outcomes (International Knee Documentation Committee subjective score), clinical measures (hamstring strength, quadriceps strength, and side-to-side knee laxity), and functional outcomes (single-leg hop) were also measured at 6 to 9 months after surgery. Univariate and multivariable analyses were performed to determine the odds ratios (ORs) for revision surgery based on the qMRI and non-imaging variables. Patient age and medial posterior tibial slope values were included as covariates. RESULTS: In total, 119 patients (97%), with a median age of 17.6 years, underwent MRI between 6 and 9 months postoperatively. Sixteen of 119 patients (13%) required revision ACL surgery. In univariate analyses, higher International Knee Documentation Committee subjective score at 6 to 9 months postoperatively (OR = 1.66 per 10-point increase; P = .035) and lower qMRI-based predicted failure load (OR = 0.66 per 100-N increase; P = .014) were associated with increased risk of revision surgery. In the multivariable model, when adjusted for age and posterior tibial slope, the qMRI-based predicted failure load was the only significant predictor of revision surgery (OR = 0.71 per 100 N; P = .044). CONCLUSION: Quantitative MRI-based predicted failure load of the healing ACL was a significant predictor of the risk of revision within 2 years after BEAR surgery. The current findings highlight the potential utility of early qMRI in the postoperative management of patients undergoing the BEAR procedure.

Effects of Initial Graft Tension and Patient Sex on Knee Osteoarthritis Outcomes After ACL Reconstruction: A Randomized Controlled Clinical Trial With 10- to 12-Year Follow-up.

BACKGROUND: The initial graft tension applied during anterior cruciate ligament (ACL) graft fixation may promote posttraumatic osteoarthritis (PTOA). PURPOSE/HYPOTHESIS: This study sought to assess the effect of initial graft tension and patient sex on PTOA outcomes at 10 to 12 years after ACL reconstruction (ACLR). The hypothesis was that there would be no group- or sex-based differences in outcomes. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Patients were randomized to receive ACLR with a low or high initial graft tension. Outcomes were evaluated at 10 to 12 years postoperatively and compared with a matched, uninjured control group. Outcomes included clinical assessments (anteroposterior [AP] knee laxity measurement, International Knee Documentation Committee [IKDC] examination score), a functional assessment (single-leg hop for distance), patient-reported outcomes (Knee injury and Osteoarthritis Outcome Score [KOOS], 36-Item Short Form Health Survey, Tegner activity level, patient satisfaction), and PTOA imaging (Osteoarthritis Research Society International [OARSI] radiographic score and Whole-Organ Magnetic Resonance Imaging Score [WORMS]). Two-way mixed-model analyses of variance were used to evaluate differences in outcomes between tension groups and the control group and between female and male patients. RESULTS: Both tension groups scored worse than the control group for the IKDC examination (P≤ .021), KOOS (Pain, Activities of Daily Living, Sport/Recreation, and Quality of Life subscales) (P≤ .049), and WORMS difference score (P≤ .042). The low-tension group scored worse than the control group for KOOS Symptoms (P = .016) and the OARSI difference score (P = .015). The index limb had worse scores than the contralateral limb within the high-tension group for AP laxity (P = .030) and hop deficit (P = .011). This result was also observed within both tension groups for the WORMS (P≤ .050) and within the low-tension group for the OARSI score (P = .001). Male patients had higher Tegner scores (mean ± SE) relative to female patients (male, 5.49 ± 1.88; female, 4.45 ± 1.65) and worse OARSI difference scores (male, 1.89 ± 5.38; female, 0.244 ± 0.668) (P = .007 and .034, respectively). However, no significant differences were detected between tension groups for any of the outcomes measured. CONCLUSION: Overall, ACLR failed to prevent PTOA regardless of initial graft tension. However, male patients treated with a low initial graft tension may be at greater risk for PTOA. These results do not support the hypothesis of no sex differences in outcomes at 10 to 12 years after ACLR.

Design Features and Rationale of the BEAR-MOON (Bridge-Enhanced ACL Restoration Multicenter Orthopaedic Outcomes Network) Randomized Clinical Trial.

BACKGROUND: BEAR (bridge-enhanced anterior cruciate ligament [ACL] restoration), a paradigm-shifting technology to heal midsubstance ACL tears, has been demonstrated to be effective in a single-center 2:1 randomized controlled trial (RCT) versus hamstring ACL reconstruction. Widespread dissemination of BEAR into clinical practice should also be informed by a multicenter RCT to demonstrate exportability and compare efficacy with bone--patellar tendon-bone (BPTB) ACL reconstruction, another clinically standard treatment. PURPOSE: To present the design and initial preparation of a multicenter RCT of BEAR versus BPTB ACL reconstruction (the BEAR: Multicenter Orthopaedic Outcomes Network [BEAR-MOON] trial). Design and analytic issues in planning the complex BEAR-MOON trial, involving the US National Institute of Arthritis and Musculoskeletal and Skin Diseases, the US Food and Drug Administration, the BEAR implant manufacturer, a data and safety monitoring board, and institutional review boards, can usefully inform both clinicians on the trial's strengths and limitations and future investigators on planning of complex orthopaedic studies. STUDY DESIGN: Clinical trial. METHODS: We describe the distinctive clinical, methodological, and operational challenges of comparing the innovative BEAR procedure with the well-established BPTB operation, and we outline the clinical motivation, experimental setting, study design, surgical challenges, rehabilitation, outcome measures, and planned analysis of the BEAR-MOON trial. RESULTS: BEAR-MOON is a 6-center, 12-surgeon, 200-patient randomized, partially blinded, noninferiority RCT comparing BEAR with BPTB ACL reconstruction for treating first-time midsubstance ACL tears. Noninferiority of BEAR relative to BPTB will be claimed if the total score on the International Knee Documentation Committee (IKDC) subjective knee evaluation form and the knee arthrometer 30-lb (13.61-kg) side-to-side laxity difference are both within respective margins of 16 points for the IKDC and 2.5 mm for knee laxity. CONCLUSION: Major issues include patient selection, need for intraoperative randomization and treatment-specific postoperative physical therapy regimens (because of fundamental differences in surgical technique, initial stability construct, and healing), and choice of noninferiority margins for short-term efficacy outcomes of a novel intervention with evident short-term advantages and theoretical, but unverified, long-term benefits on other dimensions.

Long-term outcomes of anterior cruciate ligament reconstruction surgery: 2020 OREF clinical research award paper.

ACL injuries place the knee at risk for post-traumatic osteoarthritis (PTOA) despite surgical anterior cruciate ligament (ACL) reconstruction. One parameter thought to affect PTOA risk is the initial graft tension. This randomized controlled trial (RCT) was designed to compare outcomes between two graft tensioning protocols that bracket the range commonly used. At 7 years postsurgery, we determined that most outcomes between the two tension groups were not significantly different, that they were inferior to an uninjured matched control group, and that PTOA was progressing in both groups relative to controls. The trial database was also leveraged to gain insight into mechanisms of PTOA following ACL injury. We determined that the inflammatory response at the time of injury undermines one of the joint's lubricating mechanisms. We learned that patients continue to protect their surgical knee 5 years postinjury compared to controls during a jump-pivot activity. We also established that presurgical knee function and mental health were correlated with symptomatic PTOA at 7 years, that there were specific anatomical factors associated with poor outcomes, and that there were no changes in outcomes due to tunnel widening in patients receiving hamstring tendon autografts. We also validated a magnetic resonance imaging technique to noninvasively assess graft strength. In conclusion, the RCT determined that initial graft tensioning does not have a major influence on 7-year outcomes. Therefore, surgeons can reconstruct the ACL using a graft tensioning protocol that is within the window of the two graft tensioning techniques evaluated in this RCT.

Evaluation of Graft Tensioning Effects in Anterior Cruciate Ligament Reconstruction between Hamstring and Bone-Patellar Tendon Bone Autografts.

This article investigates the clinical, functional, and radiographic outcomes in anterior cruciate ligament (ACL) reconstruction patients over 7 years to determine the effects of initial graft tension on outcomes when using patellar tendon (bone-tendon-bone [BTB]) and hamstring tendon (HS) autografts. Ninety patients, reconstructed with BTB or HS, were randomized using two initial graft tension protocols: (1) normal anteroposterior (AP) laxity ("low-tension"; n = 46) and (2) AP laxity overconstrained by 2 mm ("high-tension"; n = 44). Seventy-two patients had data available at 7 years, with 9 excluded for graft failure. Outcomes included the Knee Injury and Osteoarthritis Outcome Score, Short-Form-36 (SF-36), and Tegner activity scale. Clinical outcomes included KT-1000S and International Knee Documentation Committee examination score; and functional outcomes included 1-leg hop distance and peak knee extensor torque. Imaging outcomes included medial joint space width, Osteoarthritis Research Society International radiographic score, and Whole-Organ Magnetic Resonance Score. There were significantly improved outcomes in the high-tension compared with the low-tension HS group for SF-36 subset scores for bodily pain (p = 0.012), social functioning (p = 0.004), and mental health (p = 0.014) 84 months postsurgery. No significant differences in any outcome were found within the BTB groups. Tegner activity scores were also significantly higher for the high-tension HS group compared with the low-tension (6.0 vs. 3.8, p = 0.016). Patients with HS autografts placed in high tension had better outcomes relative to low tension for Tegner activity score and SF-36 subset scores for bodily pain, social functioning, and mental health. For this reason, we recommend that graft fixation be performed with the knee at 30-degree flexion ("high-tension" condition) when reconstructing the ACL with HS autograft.

Anabolic steroid use in adolescents: identification of those at risk and strategies for prevention.

Success in sports is often defined by winning, which drives athletes to use performance-enhancing drugs (PEDs) to gain an advantage over opponents. Over the past 20 years, use of PEDs by Olympic and professional athletes has led to public discussion regarding potential negative health effects and ethical implications of their use. Unfortunately, PEDs are not isolated to professional athletes, as PED use in adolescents has increased dramatically. Many professional organizations, including the American Academy of Orthopaedic Surgeons (AAOS), have taken a stance against PED use in sports. The AAOS believes neither anabolic steroids nor their precursors should be used to enhance performance or appearance, and that these substances should be banned in all sports programs. Pediatricians and orthopedists are often the first physicians to see these young athletes. It is critical for these physicians to recognize the significance of the problem, have the knowledge to inform adolescents, dissuade them from future use, and provide viable alternatives for meeting performance goals.

Bridge-Enhanced Anterior Cruciate Ligament Repair: The Next Step Forward in ACL Treatment.

Anterior cruciate ligament (ACL) injuries are common in young and active patients. In this patient population, surgical treatment with an autograft tendon is recommended to reconstruct a new ACL. ACL reconstruction has a high patient satisfaction, improved patient reported outcomes and allows young patients to return to an active lifestyle, including sports. However, long-term follow-up shows these patients are at higher risk for degenerative arthritis, frequently at a young age. Recent research has focused on re-investigating the utility of performing an ACL repair rather than a reconstruction in the hopes that maintaining a patient's native ligament may not only restore knee stability, but provide improved knee kinematics and lessen the risk of late osteoarthritis and also limit donor site morbidity from autograft harvests. Historically, patients undergoing ACL repair suffered poor outcomes due to issues with intra-articular healing of the ligament; but now, with new bioengineering techniques, bridge-enhanced ACL repairs may provide a feasible alternative in the treatment of ACL injuries.

Digital radiographic assessment of tibiofemoral joint space width: a variance component analysis.

This study aimed to evaluate sources of variability when the metatarsal-phalangeal (MTP) semiflexed radiographic technique is used to measure the tibiofemoral joint space width in the medial and lateral compartments of the knee. Three independent digital MTP radiographs were obtained from both knees of 9 participants. The joint space widths of both compartments of each knee were measured 3 times by 2 independent examiners. Intraclass correlation coefficients were high between repeated radiographs, between examiners, and within examiners (range, 0.91-0.98). These 3 error components accounted for 9% and 14% of the total variance for the medial and lateral compartments, respectively. The estimated SDs across radiographs for the medial and lateral compartments were 0.093 mm and 0.155 mm. The digital radiographic technique based on the MTP view is a simple and reliable technique for measuring the joint space width that can be readily used to track longitudinal changes in cartilage thickness after knee joint surgery.

Anatomic Features of the Tibial Plateau Predict Outcomes of ACL Reconstruction Within 7 Years After Surgery.

BACKGROUND: Multiple anatomic features of the femoral condyles and tibial plateau have been shown to influence knee biomechanics and risk of anterior cruciate ligament (ACL) injury. However, it remains unclear how these anatomic factors affect the midterm outcomes of ACL reconstruction. HYPOTHESIS: Decreased femoral notch width, increased posterior and coronal slopes, and decreased concavity of the tibial plateau are associated with inferior clinical, patient-reported, and osteoarthritis-related outcomes 7 years after ACL reconstruction. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Prospectively collected data from 44 patients who did not have a subsequent graft or contralateral ACL failure within 7 years after unilateral ACL reconstruction were reviewed (mean ± SD age, 23.7 ± 9.2 years; 64% women). Notch width (after notchplasty), posterior slopes of the medial and lateral tibial plateau, maximum depth of the medial tibial plateau, and coronal tibial slope were measured from magnetic resonance images. Anatomic predictors of side-to-side differences in anterior-posterior knee laxity, Knee injury and Osteoarthritis Outcome Score (KOOS), medial joint space width, and side-to-side differences in Osteoarthritis Research Society International (OARSI) x-ray score, measured at 7 years, were identified with linear regression (bivariate) and stepwise regression (multivariate). RESULTS: Increased posterior slope of the lateral tibial plateau was associated with increased side-to-side difference in knee laxity (bivariate model only), increased side-to-side difference in the OARSI score, and decreased KOOS subscores ( R2 > .10, P < .05). Increased posterior slope of the medial tibial plateau was associated with a higher side-to-side difference in the OARSI x-ray score (bivariate model only) and lower KOOS subscores ( R2 > .11, P < .03). Increased coronal tibial slope was associated with lower KOOS subscores ( R2 > .11, P < .03). Decreased medial tibial depth was associated with increased knee laxity as well as decreased KOOS subscores (ie, quality of life and symptoms; R2 > .12, P < .03). Postoperative notch width was not a significant predictor for any surgical outcome. None of the anatomic features were predictive of medial joint space width narrowing. CONCLUSION: Results partially support the hypothesis and highlight the importance of knee anatomy on several outcomes of ACL reconstruction among patients without subsequent graft or contralateral ACL injures. Increasing slopes in the coronal and sagittal planes with decreasing concavity of the medial tibial plateau lead to less favorable outcomes 7 years after surgery.

Tibiofemoral compression force differences using laxity- and force-based initial graft tensioning techniques in the anterior cruciate ligament-reconstructed cadaveric knee.

PURPOSE: Our purpose was to document the tibiofemoral (TF) compression forces produced during clinical initial graft tension protocols. METHODS: An image analysis system was used to track the position of the tibia relative to the femur in 11 cadaveric knees. TF compression forces were quantified by use of thin-film pressure sensors. Before anterior cruciate ligament (ACL) reconstructions were performed with patellar tendon grafts, measurements of TF compression force were obtained from the ACL-intact knee with knee flexion. ACL reconstructions were then performed by use of "force-based" and "laxity-based" graft tension approaches. Within each approach, high- and low-tension conditions were compared with the ACL-intact condition over the range of knee flexion angles. RESULTS: The TF compression forces for all initial graft tension conditions were significantly greater than those of the normal knee when the knee was in full extension (0 degrees ). The TF compression forces produced with the laxity-based approach were greater than those produced with the force-based approach. However, the laxity-based approach was necessary to restore normal laxity at the time of surgery. CONCLUSIONS: The results of this study show that initial graft tension conditions influence TF compressive forces at the time of surgery and that clinically relevant initial graft tension conditions produce different TF compressive forces. CLINICAL RELEVANCE: This study showed that the TF compression forces were greater in the ACL-reconstructed knee for all of the initial graft tension conditions when compared with the ACL-intact knee and that clinically relevant initial graft tension conditions produce different TF compressive forces.

Tibial tunnel widening following anterior cruciate ligament reconstruction: A retrospective seven-year study evaluating the effects of initial graft tensioning and graft selection.

PURPOSE: To investigate tibial tunnel widening in ACL reconstruction patients over seven years to establish the effects of initial graft tension on tibial widening and clinical outcomes when using both patellar tendon (BTB) and hamstring tendon (HS) grafts. METHODS: Ninety patients, who were reconstructed with BTB or HS autografts, were randomized using one of two initial graft tension protocols; 1) tensioned to restore normal anteroposterior laxity ("low-tension"; n = 46) and 2) tensioned to over-constrain anteroposterior (AP) laxity by two millimeters ("high-tension"; n = 44). Seventy patients had post-surgical data with 45 available for review at seven years. Tunnel widening was assessed via radiographs at one-, three-, and seven-year follow-up. Patient-reported outcomes were compared. RESULTS: The mean ±â€¯95% confidence intervals of the initial diameters for the BTB autografts were 10.3 ±â€¯0.5 mm (Low-tension) and 10.2 ±â€¯0.6 mm (High-tension) with final diameters of 10.8 ±â€¯0.6 mm (Low-tension) and 9.9 ±â€¯0.6 mm (High-tension). The initial diameters for HS autografts were 8.1 ±â€¯0.9 mm (Low-tension) and 8.4 ±â€¯0.7 mm (High-tension) with final diameters of 11.5 ±â€¯1.1 mm (Low-tension) and 11.1 ±â€¯0.9 mm (High-tension). For subjects with HS autografts, mean tunnel diameters significantly changed over time (p < .001); no significant changes were observed in BTB autografts (p = .29). Change in diameter of the HS autograft group remained significantly greater than the BTB group at all time points for both tension groups (p < .05). No differences in patient-reported outcomes were found between tension groups or graft types. CONCLUSIONS: Patients who underwent ACL-R with HS autograft exhibited tibial tunnel widening over seven years. Patients with BTB autografts did not experience widening, regardless of initial graft tension. Patient-reported outcomes were equivalent.

Preoperative KOOS and SF-36 Scores Are Associated With the Development of Symptomatic Knee Osteoarthritis at 7 Years After Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Anterior cruciate ligament (ACL) tears are associated with the development of knee osteoarthritis despite ACL reconstruction surgery. However, little evidence is available to determine which patients will develop symptomatic knee osteoarthritis. PURPOSE: To determine if preoperative outcome measures-KOOS (Knee injury and Osteoarthritis Outcome Score) and SF-36 (36-item Short Form Health Survey)-were associated with the development of a symptomatic knee 7 years after ACL reconstruction. A secondary goal was to examine the relationship between imaging evidence of knee osteoarthritis and development of knee pain. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Prospectively collected data from 72 patients were reviewed with 7-year follow-up after unilateral ACL reconstruction. Patients were divided into symptomatic and asymptomatic groups based on the previously defined KOOS pain ≤72. Demographic variables and preoperative KOOS and SF-36 scores were compared between groups. Radiographic and magnetic resonance imaging data were used to evaluate differences in joint space width, Osteoarthritis Research Society International radiographic score, and the Whole-Organ Magnetic Resonance Imaging Score between groups. Univariate and multivariate analyses were performed to identify potential predictors of pain at 7-year follow-up. Wilcoxon sum rank and t tests were used to compare imaging findings between the symptomatic and asymptomatic patients at 7 years. RESULTS: According to KOOS pain, 7 of the 72 patients available at 7-year follow-up formed the symptomatic group. No differences were found between groups in regard to demographic variables or intraoperative findings. In multivariate analysis, lower preoperative scores for KOOS sports/recreation ( P = .005) and SF-36 mental health ( P = .025) were associated with a painful knee at 7 years, with increased odds of 82% and 68% per 10-unit decrease, respectively. The Whole-Organ Magnetic Resonance Imaging Score at 7 years showed evidence of osteoarthritic changes in the symptomatic group as compared with the asymptomatic group ( P = .047). However, there were no significant differences in the Osteoarthritis Research Society International radiographic score ( P = .051) or joint space width ( P = .488) between groups. CONCLUSION: Lower preoperative KOOS and SF-36 scores were associated with those patients who developed symptomatic knee osteoarthritis 7 years after ACL reconstruction.

The meniscal roots: gross anatomic correlation with 3-T MRI findings.

OBJECTIVE: The purpose of this article is to highlight the normal anatomic features of the meniscal roots on photographs of dissected cadaveric knee specimens and 3-T MR images. CONCLUSION: The meniscal roots, which are critical attachment sites of the medial and lateral menisci to the central tibial plateau, are well-visualized on intermediate-weighted, turbo spin-echo 3-T MRI and can be identified in proximity to the tibial insertions of the anterior and posterior cruciate ligaments.

Effects of initial graft tension on the tibiofemoral compressive forces and joint position after anterior cruciate ligament reconstruction.

BACKGROUND: The initial tension applied to an anterior cruciate ligament graft at the time of fixation modulates knee motion and the tibiofemoral compressive loads. PURPOSE: To establish the relationships between initial graft tension, tibiofemoral compressive force, and the neutral tibiofemoral position in the cadaveric knee. STUDY DESIGN: Controlled laboratory study. METHODS: The tibiofemoral compressive forces and joint positions were determined in the anterior cruciate ligament-intact knee at 0 degrees , 20 degrees , and 90 degrees of knee flexion. The anterior cruciate ligament was excised and reconstructed with a patellar tendon graft using graft tensions of 1, 15, 30, 60, and 90 N applied at 0 degrees , 20 degrees , and 90 degrees of knee flexion. The compressive forces and neutral positions were compared between initial tension conditions and the anterior cruciate ligament-intact knee. RESULTS: Increasing initial graft tension increased the tibiofemoral compressive forces. The forces in the medial compartment were 1.8 times those in the lateral compartment. The compressive forces were dependent on the knee angle at which the tension was applied. The greatest compressive forces occurred when the graft was tensioned with the knee in extension. An increase in initial graft tension caused the tibia to rotate externally compared with the anterior cruciate ligament-intact knee (1.5 degrees and 7.7 degrees of external rotation when tensioned to 90 N at 0 degrees and 90 degrees of knee flexion, respectively). Increases in initial graft tension also caused a significant posterior translation of the tibia relative to the femur (0.9 and 5.3 mm of posterior translation when tensioned to 90 N at 0 degrees and 90 degrees of knee flexion, respectively). CONCLUSION: Different initial graft tension protocols produced predictable changes in the tibiofemoral compressive forces and joint positions. CLINICAL RELEVANCE: The tibiofemoral compressive force and neutral joint position were best replicated with a low graft tension (1-15 N) when using a patellar tendon graft.

Intra-articular anesthesia and knee muscle response.

BACKGROUND: Many receptors located within the intra-articular knee structures contribute to the neuromuscular responses of the knee. The purpose was to compare the automatic postural response induced by a perturbation at the foot before and after an intra-articular injection of a local anesthetic (bupivicaine), after a saline (sham) injection, and after no intra-articular injection (control) in the knee. METHODS: Muscle onset latencies and automatic response magnitudes for the vastus medialis, vastus lateralis, biceps femoris, medial hamstrings, tibialis anterior, and gastrocnemius were measured using electromyography (EMG) when anteriorly directed perturbations were applied to the feet of 30 subjects. All subjects then received a lidocaine skin injection followed by: an intra-articular bupivicaine injection (treatment group); an intra-articular saline injection (sham group); or no injection (control group), depending on their randomized group assignment. The perturbation tests were then repeated. FINDINGS: Muscle onset latencies and automatic response magnitudes did not change as a result of the intra-articular injections. Latencies were significantly greater for the vastus medialis and vastus lateralis when compared to the medial hamstrings, biceps femoris and tibialis anterior (P<0.001). Automatic response magnitudes for the tibialis anterior were significantly greater than those of the hamstrings, which were greater than those of the quadriceps (P<0.001). INTERPRETATION: There were no differences in muscle response when anteriorly directed perturbations were applied to the foot with or without an injection of local anesthetic in the knee. Intra-articular receptors were either unaffected by the anesthetic or the extra-articular receptors or receptors of the other joints were able to compensate for their loss.

Porcine small intestine submucosa for repair of goat meniscal defects.

This study evaluated the effectiveness of small intestine submucosa used as a graft to fill surgically created meniscal defects in a large animal model. Four goats underwent unilateral interior subtotal meniscectomies (approximately 70%) within the avascular portion of the medial meniscus. The contralateral meniscus acted as a control. Grafts of porcine small intestine submucosa were trimmed to fill the resected defects and sutured into place. After surgery the operated knees were casted in partial flexion to limit weight bearing on the affected limb. All of the animals were sacrificed at 12 weeks at which point meniscal regeneration and articular cartilage degradation were evaluated by gross and histologic examination. Grossly, the defects in the small intestine submucosa-grafted goats were partially filled with meniscal-appearing connective tissue. Histologically, the replacement tissue was typified by the presence of dense, cellular, irregularly organized connective tissue. Evaluation of the articular cartilage displayed increased degeneration in the grafted compartment of the operative knees. Each of the operative menisci partially regenerated. The grafts were conducive to repopulation with host meniscal elements. Despite partial meniscal regeneration, comparatively more articular cartilage degeneration in the treated knees was observed than in the untreated contralateral controls.

Orthopaedic Resident Preparation and Confidence in Treating On-Field Injuries.

BACKGROUND: Orthopaedic surgery residents may cover athletic events, although the training provided to prepare residents for this role and oversight from attending physicians during these activities is not well understood. PURPOSE: To survey orthopaedic residents about the training provided by their residency program for on-field athletic coverage and to understand their levels of preparation for this role and confidence in treating commonly encountered on-field conditions. STUDY DESIGN: Descriptive epidemiology study. METHODS: An anonymous survey was emailed to residents in all American College of Graduate Medical Education-accredited, allopathic, nonmilitary orthopaedic surgery residency programs. This survey queried residents about their demographics, the opportunities their residencies require or allow for athletic coverage, their level of preparation for serving an on-field physician, and their comfort level with treating a number of on-field conditions. Likert-type scales were used to assess resident comfort level for treating 13 orthopaedic and nonorthopaedic conditions as well as their perceived level of preparedness. RESULTS: Of 148 residency programs contacted, 57 programs responded (39%). Of the 57 programs responding, 51 (89.5%) allowed or required residents to cover athletic events, and 27 of 51 (52.9%) reported that training to prepare for this role was provided. Only 6 of 24 programs without training available (25%) had direct attending supervision of residents at all athletic events. Residents who answered that their residency programs mandate training prior to their participation in athletic coverage activities reported a higher level of preparation for this role than those with no training, optional training, or those who were unsure of their training requirement (P < .0001, P = .035, and P = .013, respectively). In addition, the more senior the resident was, the higher the level of confidence was in treating all orthopaedic and some nonorthopaedic conditions. Residents who had mandatory training displayed a higher comfort level in treating on-field orthopaedic and nonorthopaedic conditions than those without training. CONCLUSION: Formal training of orthopaedic residents prior to their covering athletic events can improve confidence in treating orthopaedic and nonorthopaedic conditions. Many programs do not ensure that residents are familiar with key and potentially life-saving equipment. An opportunity exists to improve resident education.