Richard A. White

Effect of Graft Choice on the Outcome of Revision Anterior Cruciate Ligament Reconstruction in the Multicenter ACL Revision Study (MARS) Cohort

Background: Most surgeons believe that graft choice for anterior cruciate ligament (ACL) reconstruction is an important factor related to outcome; however, graft choice for revision may be limited due to previously used grafts. Hypotheses: Autograft use would result in increased sports function, increased activity level, and decreased osteoarthritis symptoms (as measured by validated patient-reported outcome instruments). Autograft use would result in decreased graft failure and reoperation rate 2 years after revision ACL reconstruction. Study Design: Cohort study; Level of evidence, 2. Methods: Patients undergoing revision ACL reconstruction were identified and prospectively enrolled by 83 surgeons at 52 sites. Data collected included baseline demographics, surgical technique, pathologic abnormalities, and the results of a series of validated, patient-reported outcome instruments (International Knee Documentation Committee [IKDC], Knee injury and Osteoarthritis Outcome Score [KOOS], Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], and Marx activity rating score). Patients were followed up at 2 years and asked to complete the identical set of outcome instruments. Incidences of additional surgery and reoperation due to graft failure were also recorded. Multivariate regression models were used to determine the predictors (risk factors) of IKDC, KOOS, WOMAC, Marx scores, graft rerupture, and reoperation rate at 2 years after revision surgery. Results: A total of 1205 patients (697 [58%] males) were enrolled. The median age was 26 years. In 88% of patients, this was their first revision, and 341 patients (28%) were undergoing revision by the surgeon who had performed the previous reconstruction. The median time since last ACL reconstruction was 3.4 years. Revision using an autograft was performed in 583 patients (48%), allograft was used in 590 (49%), and both types were used in 32 (3%). Questionnaire follow-up was obtained for 989 subjects (82%), while telephone follow-up was obtained for 1112 (92%). The IKDC, KOOS, and WOMAC scores (with the exception of the WOMAC stiffness subscale) all significantly improved at 2-year follow-up (P < .001). In contrast, the 2-year Marx activity score demonstrated a significant decrease from the initial score at enrollment (P < .001). Graft choice proved to be a significant predictor of 2-year IKDC scores (P = .017). Specifically, the use of an autograft for revision reconstruction predicted improved score on the IKDC (P = .045; odds ratio [OR] = 1.31; 95% CI, 1.01-1.70). The use of an autograft predicted an improved score on the KOOS sports and recreation subscale (P = .037; OR = 1.33; 95% CI, 1.02-1.73). Use of an autograft also predicted improved scores on the KOOS quality of life subscale (P = .031; OR = 1.33; 95% CI, 1.03-1.73). For the KOOS symptoms and KOOS activities of daily living subscales, graft choice did not predict outcome score. Graft choice was a significant predictor of 2-year Marx activity level scores (P = .012). Graft rerupture was reported in 37 of 1112 patients (3.3%) by their 2-year follow-up: 24 allografts, 12 autografts, and 1 allograft and autograft. Use of an autograft for revision resulted in patients being 2.78 times less likely to sustain a subsequent graft rupture compared with allograft (P = .047; 95% CI, 1.01-7.69). Conclusion: Improved sports function and patient-reported outcome measures are obtained when an autograft is used. Additionally, use of an autograft shows a decreased risk in graft rerupture at 2-year follow-up. No differences were noted in rerupture or patient-reported outcomes between soft tissue and bone–patellar tendon–bone grafts. Surgeon education regarding the findings of this study has the potential to improve the results of revision ACL reconstruction.

A New Operative Approach in the Correction of External Coxa Saltans The Snapping Hip

Background External snapping hip is an entity that describes a snap that is felt on the lateral aspect of the hip. Several surgical interventions are described. Hypothesis The external snapping hip can be corrected with a simple procedure that is minimally invasive and less demanding than other techniques. Study Design This is a retrospective review from June 1994 until January 2002 looking at released external snapping hips. Methods There were 16 patients with 17 hips; follow-up was in 15 patients with 16 snapping hips. Twelve patients with 13 hips were contacted by telephone interview, and 3 were followed up by their most recent chart note. All underwent the same procedure performed by the senior author. The questionnaire was conducted at an average of 32.5 months after surgery (range, 9-74 months). For 3 patients, chart-only follow-up was at 6 weeks, 3 months, and 6 months, respectively. Results Fourteen of 16 hips remained asymptomatic after final surgical release (2 hips needed a second release). All patients contacted by telephone would undergo the same procedure again if faced with the same symptoms. Conclusions This technique is simpler than most of those previously described with the benefit of no formal postoperative regimen and comparable results.

Allograft Compared with Autograft Infection Rates in Primary Anterior Cruciate Ligament Reconstruction

BACKGROUNDnInjuries to the anterior cruciate ligament are the most common surgically treated knee ligament injury. There is no consensus regarding the optimal graft choice between allograft and autograft tissue. Postoperative septic arthritis is an uncommon complication after anterior cruciate ligament reconstruction. The purpose of this study was to compare infection rates between procedures with use of allograft and autograft tissue in primary anterior cruciate ligament reconstruction.nnnMETHODSnA combined prospective and retrospective multicenter cohort study was performed over a three-year period. Graft selection was determined by the individual surgeon. Inclusion and exclusion criteria were equivalent for the two groups (allograft and autograft tissue). Data collected included demographic characteristics, clinical information, and graft details. Patients were followed for a minimum of 5.5 months postoperatively. Our primary outcome was intra-articular infection following anterior cruciate ligament reconstruction.nnnRESULTSnOf the 1298 patients who had anterior cruciate ligament reconstruction during the study period, 861 met the criteria for inclusion and formed the final study group. Two hundred and twenty-one patients (25.6%) received an autograft, and 640 (74.3%) received an allograft. There were no cases of septic arthritis in either group. The 95% confidence interval was 0% to 0.57% for the allograft group and 0% to 1.66% for the autograft group. The rate of superficial infections in the entire study group was 2.32%. We did not identify a significant difference in the rate of superficial infections between autograft and allograft reconstruction in our study group.nnnCONCLUSIONSnWhile the theoretical risk of disease transmission inherent with allograft tissue cannot be eliminated, we found no increased clinical risk of infection with the use of allograft tissue compared with autologous tissue for primary anterior cruciate ligament reconstruction.

Osteoarthritis classification scales: Interobserver reliability and arthroscopic correlation

BACKGROUNDnOsteoarthritis of the knee is commonly diagnosed and monitored with radiography. However, the reliability of radiographic classification systems for osteoarthritis and the correlation of these classifications with the actual degree of confirmed degeneration of the articular cartilage of the tibiofemoral joint have not been adequately studied.nnnMETHODSnAs the Multicenter ACL (anterior cruciate ligament) Revision Study (MARS) Group, we conducted a multicenter, prospective longitudinal cohort study of patients undergoing revision surgery after anterior cruciate ligament reconstruction. We followed 632 patients who underwent radiographic evaluation of the knee (an anteroposterior weight-bearing radiograph, a posteroanterior weight-bearing radiograph made with the knee in 45° of flexion [Rosenberg radiograph], or both) and arthroscopic evaluation of the articular surfaces. Three blinded examiners independently graded radiographic findings according to six commonly used systems-the Kellgren-Lawrence, International Knee Documentation Committee, Fairbank, Brandt et al., Ahlbäck, and Jäger-Wirth classifications. Interobserver reliability was assessed with use of the intraclass correlation coefficient. The association between radiographic classification and arthroscopic findings of tibiofemoral chondral disease was assessed with use of the Spearman correlation coefficient.nnnRESULTSnOverall, 45° posteroanterior flexion weight-bearing radiographs had higher interobserver reliability (intraclass correlation coefficient = 0.63; 95% confidence interval, 0.61 to 0.65) compared with anteroposterior radiographs (intraclass correlation coefficient = 0.55; 95% confidence interval, 0.53 to 0.56). Similarly, the 45° posteroanterior flexion weight-bearing radiographs had higher correlation with arthroscopic findings of chondral disease (Spearman rho = 0.36; 95% confidence interval, 0.32 to 0.39) compared with anteroposterior radiographs (Spearman rho = 0.29; 95% confidence interval, 0.26 to 0.32). With respect to standards for the magnitude of the reliability coefficient and correlation coefficient (Spearman rho), the International Knee Documentation Committee classification demonstrated the best combination of good interobserver reliability and medium correlation with arthroscopic findings.nnnCONCLUSIONSnThe overall estimates with the six radiographic classification systems demonstrated moderate (anteroposterior radiographs) to good (45° posteroanterior flexion weight-bearing radiographs) interobserver reliability and medium correlation with arthroscopic findings. The International Knee Documentation Committee classification assessed with use of 45° posteroanterior flexion weight-bearing radiographs had the most favorable combination of reliability and correlation.nnnLEVEL OF EVIDENCEnDiagnostic Level I. See Instructions for Authors for a complete description of levels of evidence.

Meniscal and Articular Cartilage Predictors of Clinical Outcome After Revision Anterior Cruciate Ligament Reconstruction

Background: Revision anterior cruciate ligament (ACL) reconstruction has been documented to have worse outcomes compared with primary ACL reconstructions. Purpose/Hypothesis: The purpose of this study was to determine if the prevalence, location, and/or degree of meniscal and chondral damage noted at the time of revision ACL reconstruction predicts activity level, sports function, and osteoarthritis symptoms at 2-year follow-up. The hypothesis was that meniscal loss and high-grade chondral damage noted at the time of revision ACL reconstruction will result in lower activity levels, decreased sports participation, more pain, more stiffness, and more functional limitation at 2 years after revision surgery. Study Design: Cohort study; Level of evidence, 2. Methods: Between 2006 and 2011, a total of 1205 patients who underwent revision ACL reconstruction by 83 surgeons at 52 hospitals were accumulated for study of the relationship of meniscal and articular cartilage damage to outcome. Baseline demographic and intraoperative data, including the International Knee Documentation Committee (IKDC) subjective knee evaluation, Knee injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Marx activity score, were collected initially and at 2-year follow-up to test the hypothesis. Regression analysis was used to control for age, sex, body mass index, smoking status, activity level, baseline outcome scores, revision number, time since last ACL reconstruction, incidence of having a previous ACL reconstruction on the contralateral knee, previous and current meniscal and articular cartilage injury, graft choice, and surgeon years of experience to assess the meniscal and articular cartilage risk factors for clinical outcomes 2 years after revision ACL reconstruction. Results: At 2-year follow-up, 82% (989/1205) of the patients returned their questionnaires. It was found that previous meniscal injury and current articular cartilage damage were associated with the poorest outcomes, with prior lateral meniscectomy and current grade 3 to 4 trochlear articular cartilage changes having the worst outcome scores. Activity levels at 2 years were not affected by meniscal or articular cartilage pathologic changes. Conclusion: Prior lateral meniscectomy and current grade 3 to 4 changes of the trochlea were associated with worse outcomes in terms of decreased sports participation, more pain, more stiffness, and more functional limitation at 2 years after revision surgery, but they had no effect on activity levels. Registration: NCT00625885

In vitro electromagnetic stimulation to enhance cell proliferation in extracellular matrix constructs with and without metallic nanoparticles.

Extremely low frequency electromagnetic fields (ELF-EMFs) can induce beneficial effects including enhanced protein synthesis and cell proliferation on healing bone and skin wounds. This study investigated the effects of ELF-EMFs on acellular tissue constructs with and without gold nanoparticles (AuNPs) to determine if cell proliferation could be increase and thus provide an enhanced mechanism for in vitro cell seeding on tissue engineered constructs. Different sized AuNPs, 20 and 100 nm, were conjugated to acellular porcine tissue, seeded with L929 murine fibroblasts and exposed to a continuous 12 gauss, 60 Hz electromagnetic field for 2 hours each day up to 10 days. Scanning electron microscopy and cell culture assays were performed to ascertain cell proliferation and viability before and after exposure. Results indicate the ELF-EMF stimulation significantly increased cell proliferation. The presence of AuNPs did not boost the stimulatory effects, but they did demonstrated higher rates of proliferation from day 3 to day 10. In addition, unstimulated 100 nm AuNPs constructs resulted in significant increases in proliferation as compared to unstimulated crosslinked constructs. In conclusion, ELF-EMF stimulation enhanced cellular proliferation and while the presence of AuNPs did not significantly enhance this effect, AuNPs resulted in increased proliferation rates from day 3 to day 10.

Medical malpractice and the sports medicine clinician.

More individuals are participating in athletics today than ever before. Physicians treating athletes confront unique diagnostic and treatment challenges and an increased risk of legal liability. The key areas regarding liability are preparticipation examinations, determination of eligibility, evaluation of significant on-field injuries, and information disclosure. The issues surrounding preparticipation physicals and determination of eligibility are closely linked. Physicians must be prepared to seek guidance from specialists, particularly when there are cardiac, spinal, or neurologic issues. Appropriate on-field evaluation of potential concussions, spinal injuries, and heat stroke are key areas of concern for the physician. Privacy issues have become more complex in the age of federal regulation. Physicians and all athletic staff should be aware of privacy laws and ensure proper consent documentation is obtained from all athletes or their parents. All athletic programs should develop a plan that details roles and procedures to be followed in a medical emergency. Sports caregivers must take affirmative steps that better protect their patients from harm and physicians from legal liability.

Surgical Predictors of Clinical Outcomes after Revision Anterior Cruciate Ligament Reconstruction

Background: Revision anterior cruciate ligament (ACL) reconstruction has been documented to have worse outcomes compared with primary ACL reconstruction. Hypothesis: Certain factors under the control of the surgeon at the time of revision surgery can both negatively and positively affect outcomes. Study Design: Case-control study; Level of evidence, 3. Methods: Patients undergoing revision ACL reconstruction were identified and prospectively enrolled between 2006 and 2011. Data collected included baseline demographics, intraoperative surgical technique and joint disorders, and a series of validated patient-reported outcome instruments (International Knee Documentation Committee [IKDC] subjective form, Knee Injury and Osteoarthritis Outcome Score [KOOS], Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], and Marx activity rating scale) completed before surgery. Patients were followed up for 2 years and asked to complete an identical set of outcome instruments. Regression analysis was used to control for age, sex, body mass index (BMI), activity level, baseline outcome scores, revision number, time since last ACL reconstruction, and a variety of previous and current surgical variables to assess the surgical risk factors for clinical outcomes 2 years after revision ACL reconstruction. Results: A total of 1205 patients (697 male [58%]) met the inclusion criteria and were successfully enrolled. The median age was 26 years, and the median time since their last ACL reconstruction was 3.4 years. Two-year follow-up was obtained on 82% (989/1205). Both previous and current surgical factors were found to be significant contributors toward poorer clinical outcomes at 2 years. Having undergone previous arthrotomy (nonarthroscopic open approach) for ACL reconstruction compared with the 1-incision technique resulted in significantly poorer outcomes for the 2-year IKDC (P = .037; odds ratio [OR], 2.43; 95% CI, 1.05-5.88) and KOOS pain, sports/recreation, and quality of life (QOL) subscales (P ≤ .05; OR range, 2.38-4.35; 95% CI, 1.03-10.00). The use of a metal interference screw for current femoral fixation resulted in significantly better outcomes for the 2-year KOOS symptoms, pain, and QOL subscales (P ≤ .05; OR range, 1.70-1.96; 95% CI, 1.00-3.33) as well as WOMAC stiffness subscale (P = .041; OR, 1.75; 95% CI, 1.02-3.03). Not performing notchplasty at revision significantly improved 2-year outcomes for the IKDC (P = .013; OR, 1.47; 95% CI, 1.08-1.99), KOOS activities of daily living (ADL) and QOL subscales (P ≤ .04; OR range, 1.40-1.41; 95% CI, 1.03-1.93), and WOMAC stiffness and ADL subscales (P ≤ .04; OR range, 1.41-1.49; 95% CI, 1.03-2.05). Factors before revision ACL reconstruction that increased the risk of poorer clinical outcomes at 2 years included lower baseline outcome scores, a lower Marx activity score at the time of revision, a higher BMI, female sex, and a shorter time since the patient’s last ACL reconstruction. Prior femoral fixation, prior femoral tunnel aperture position, and knee flexion angle at the time of revision graft fixation were not found to affect 2-year outcomes in this revision cohort. Conclusion: There are certain surgical variables that the physician can control at the time of revision ACL reconstruction that can modify clinical outcomes at 2 years. Whenever possible, opting for an anteromedial portal or transtibial surgical exposure, choosing a metal interference screw for femoral fixation, and not performing notchplasty are associated with significantly better 2-year clinical outcomes.

In vivo bone tunnel evaluation of nanoparticle-grafts using an ACL reconstruction rabbit model.

Acellular human gracilis tendons conjugated with gold nanoparticles (AuNP) and hydroxyapatite nanoparticles (nano-HAp) were used as a graft in an anterior cruciate ligament (ACL) reconstruction rabbit model. The ACLs of 11 New Zealand rabbits were reconstructed using grafts conjugated without nanoparticles, with AuNP only, and with both AuNP and nano-HAp. Semi-quantitative histological scoring of bone tunnel portion of grafts was performed after 14 weeks. Bone tunnels were scored for graft degeneration, graft remodeling, percentage of new host fibrous connective, collateral connection, head-to-head connection, graft collagen fiber organization, new host fibrous connective tissue organization, and graft and interface vascularity. All grafts were intact at 14 weeks. Results of bone tunnel scoring indicate remodeling in all graft types with new organized host fibrous connective tissue, head-to-head connection to bone and mild inflammation associated with remodeling. Components of the 20 nm AuNP grafts have significantly more graft degeneration, more new host fibrous connective tissue, and more vascularity compared to crosslinked grafts. Comparison between femoral and tibial tunnel scores indicate more degeneration in femoral tunnels compared to tibial tunnels. Overall results indicated potentially enhanced remodeling from the use of 20 nm AuNP grafts.

Physiologic Preoperative Knee Hyperextension Is a Predictor of Failure in an Anterior Cruciate Ligament Revision Cohort: A Report From the MARS Group:

Background: The occurrence of physiologic knee hyperextension (HE) in the revision anterior cruciate ligament reconstruction (ACLR) population and its effect on outcomes have yet to be reported. Hypothesis/Purpose: The prevalence of knee HE in revision ACLR and its effect on 2-year outcome were studied with the hypothesis that preoperative physiologic knee HE ≥5° is a risk factor for anterior cruciate ligament (ACL) graft rupture. Study Design: Cohort study; Level of evidence, 2. Methods: Patients undergoing revision ACLR were identified and prospectively enrolled between 2006 and 2011. Study inclusion criteria were patients undergoing single-bundle graft reconstructions. Patients were followed up at 2 years and asked to complete an identical set of outcome instruments (International Knee Documentation Committee, Knee injury and Osteoarthritis Outcome Score, WOMAC, and Marx Activity Rating Scale) as well as provide information regarding revision ACL graft failure. A regression model with graft failure as the dependent variable included age, sex, graft type at the time of the revision ACL surgery, and physiologic preoperative passive HE ≥5° (yes/no) to assess these as potential risk factors for clinical outcomes 2 years after revision ACLR. Results: Analyses included 1145 patients, for whom 2-year follow-up was attained for 91%. The median age was 26 years, with age being a continuous variable. Those below the median were grouped as “younger” and those above as “older” (age: interquartile range = 20, 35 years), and 42% of patients were female. There were 50% autografts, 48% allografts, and 2% that had a combination of autograft plus allograft. Passive knee HE ≥5° was present in 374 (33%) patients in the revision cohort, with 52% being female. Graft rupture at 2-year follow-up occurred in 34 cases in the entire cohort, of which 12 were in the HE ≥5° group (3.2% failure rate) and 22 in the non-HE group (2.9% failure rate). The median age of patients who failed was 19 years, as opposed to 26 years for those with intact grafts. Three variables in the regression model were significant predictors of graft failure: younger age (odds ratio [OR] = 3.6; 95% CI, 1.6-7.9; P = .002), use of allograft (OR = 3.3; 95% CI, 1.5-7.4; P = .003), and HE ≥5° (OR = 2.12; 95% CI, 1.1-4.7; P = .03). Conclusion: This study revealed that preoperative physiologic passive knee HE ≥5° is present in one-third of patients who undergo revision ACLR. HE ≥5° was an independent significant predictor of graft failure after revision ACLR with a >2-fold OR of subsequent graft rupture in revision ACL surgery. Registration: NCT00625885 (ClinicalTrials.gov identifier).