Carl W. Nissen

A Prospective Study of Autologous Chondrocyte Implantation in Patients With Failed Prior Treatment for Articular Cartilage Defect of the Knee: Results of the Study of the Treatment of Articular Repair (STAR) Clinical Trial

Background This is a prospective clinical study to assess the effectiveness of autologous chondrocyte implantation in patients who failed prior treatments for articular cartilage defects of the knee. Hypothesis Autologous chondrocyte implantation provides clinical benefit in patients with failed articular cartilage treatments. Study Design Cohort study; Level of evidence, 2. Methods One hundred fifty-four patients with failed treatment for articular cartilage defects of the knee received autologous chondrocyte implantation in a multicenter, prospective study. Follow-up was 48 months. Outcomes included change from baseline in knee function, knee pain, quality of life, and overall health. Duration of benefit after autologous chondrocyte implantation was compared with the failed prior non—autologous chondrocyte implantation procedure. Safety information was recorded. Additional analyses were performed on the 2 major cohorts of prior procedures entered into the study, marrow-stimulation technique or debridement alone, to assess if there were any significant differences in baseline characteristics, outcomes, or prognosis between the 2 groups. Results One hundred twenty-six patients (82%) completed the protocol. Seventy-six percent of patients were treatment successes at study end, while 24% were deemed treatment failures. Preoperative mean knee pain score was 3.0 (SD, 1.8; 0 = severe, 10 = normal). Mean improvements were observed from baseline to all time points (P < .001) for all outcome measures. Preoperative to 48-month values, respectively, were as follows: On the Knee injury and Osteoarthritis Outcome Score subscales of pain: 48.7 to 72.2; other symptoms: 51.8 to 70.8; sports/recreation: 25.8 to 55.8; knee quality of life: 20.9 to 52.2; and activities of daily living: 58.6 to 81.0; on the Modified Cincinnati Overall Knee score: 3.3 to 6.3; on the visual analog scale: 28.8 to 69.9; and on the SF-36 Overall Physical Health 33.0 to 44.4. Results did not differ between patients whose primary surgery had been a marrow-stimulating procedure and those whose primary procedure had been a debridement alone. The median difference in duration of benefit between autologous chondrocyte implantation and the failed non—autologous chondrocyte implantation prior procedure was at least 31 months (P < .001). Seventy-six patients (49%) had subsequent surgical procedure(s), predominantly arthroscopic. Need for a subsequent surgical procedure was not predictive of failure. Conclusion Patients with moderate to large chondral lesions with failed prior cartilage treatments can expect sustained and clinically meaningful improvement in pain and function after autologous chondrocyte implantation. The subsequent surgical procedure rate observed in this study (49% overall; 40% related to autologous chondrocyte implantation) appears higher than generally reported after autologous chondrocyte implantation.

Responsiveness of the International Knee Documentation Committee Subjective Knee Form in Comparison to the Western Ontario and McMaster Universities Osteoarthritis Index, Modified Cincinnati Knee Rating System, and Short Form 36 in Patients With Focal Articular Cartilage Defects

Background The International Knee Documentation Committee Subjective Knee Form (IKDC SKF) is a patient-reported knee-specific outcome measure that has been shown to be a reliable, valid, and responsive measure for patients with a variety of knee conditions. Further testing is required to compare the reliability and responsiveness of the IKDC SKF to other commonly used patient-reported outcome measures for patients with articular cartilage lesions. Hypothesis The IKDC SKF has equal or better levels of reliability and responsiveness than the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), modified Cincinnati Knee Rating System (CKRS), and the Short Form 36 in patients with articular cartilage lesions. Study Design Cohort study (diagnosis); Level of evidence, 2. Methods Reliability was assessed by administering the 4 patient-reported outcome measures to 17 individuals who had undergone articular cartilage surgery 5 years before participation in this study. Responsiveness was determined by administering the 4 patient-reported outcome measures to 51 individuals with diagnosed focal articular cartilage defects who were scheduled to undergo surgical treatment. In both groups, the outcome measures were administered at baseline and at 6 and 12 months’ follow-up. Participants also provided a global rating of change in comparison to baseline at the 6- and 12-month follow-ups. Results Test-retest reliability coefficients were 0.91 and 0.93 for the IKDC SKF at the 6- and 12-month follow-ups, respectively. The effect sizes and standardized response means were large (>0.80) at 6 months after surgery for the WOMAC pain, physical function, and total scores and 12 months after surgery for the IKDC SKF; WOMAC pain, physical function, and total; and CKRS scores. Six months after surgery, significant differences between those who were improved compared with those who were unchanged or worse were found only for the IKDC SKF. Twelve months after surgery, significant differences between the improved and unchanged groups were found for all of the knee-specific patient-reported outcome measures. Finally, the IKDC SKF, WOMAC, and CKRS scores were able to differentiate between individuals who perceived themselves to be improved versus not improved and the minimum clinically important difference for the IKDC SKF was 6.3 at 6 months and 16.7 at 12 months. Conclusion The reliability and responsiveness of the IKDC SKF is comparable with other commonly used patient-reported outcome measures for patients with articular cartilage lesions. The IKDC SKF is a suitable alternative to other commonly used knee-specific instruments for measuring symptoms, daily function, and level of symptom-free sports activity in patients undergoing articular cartilage surgery.

A Biomechanical Comparison of the Fastball and Curveball in Adolescent Baseball Pitchers

Background The incidence of shoulder and elbow injuries in adolescent baseball players is rapidly increasing. One leading theory about this increase is that breaking pitches (such as the curveball) place increased moments on the dominant arm and thereby increase the risk of injury. Hypothesis There is no difference in the moments at the shoulder and elbow between fastball and curveball pitches in adolescent baseball pitchers. Study Design Controlled laboratory study. Methods Thirty-three adolescent baseball pitchers with a minimum of 2 years of pitching experience underwent 3-dimensional motion analysis using reflective markers aligned to bony landmarks. After a warm-up, pitchers threw either a fastball or curveball, randomly assigned, from a portable pitching mound until 3 appropriate trials were collected for each pitch technique. Kinematic and kinetic data for the upper extremities, lower extremities, thorax, and pelvis were collected and computed for both pitch types. Statistical analysis included both the paired sample t test and mixed model regression. Results There were lower moments on the shoulder and elbow when throwing a curveball versus when throwing a fastball. As expected, speed for the 2 pitches differed: fastball, 65.8 ± 4.8 mph; and curveball, 57.7 ± 6.2 mph (P <. 001). Maximal glenohumeral internal rotation moment for the fastball was significantly higher than for the curveball (59.8 ± 16.5 N·m vs 53.9 ± 15.5 N·m; P <. 0001). Similarly, the maximum varus elbow moment for the fastball was significantly higher than for the curveball (59.6 ± 16.3 N·m vs 54.1 ± 16.1 N·m; P <. 001). The wrist flexor moment was greater in the fastball, 8.3 ± 3.6 N·m, than in the curveball, 7.8 ± 3.6 N·m (P <. 001), but the wrist ulnar moment was greater in the curveball, 4.9 ± 2.0 N·m, than in the fastball, 3.2 ± 1.5 N·m (P <. 001). Relatively minor motion differences were noted at the shoulder and elbow throughout the pitching motion, while significant differences were seen in forearm and wrist motion. The forearm remained more supinated at each point in the pitching cycle for the curveball but had less overall range of motion (62° ± 20°) than with the fastball (69° ± 17°) (P <. 001), and the difference in the forearm pronation and supination moment between the pitches was not significant (P =. 104 for pronation and P =. 447 for supination). The wrist remained in greater extension during the fastball from foot contact through ball release but did not have significantly different total sagittal range of motion (53° ± 11°) when compared with the curveball (54° ± 15°) (P =. 91). Conclusion In general, the moments on the shoulder and elbow were less when throwing a curveball than when throwing a fastball. In each comparison, the fastball demonstrated higher moments for each individual pitcher for both joints. Clinical Relevance The findings based on the kinematic and kinetic data in this study suggest that the rising incidence of shoulder and elbow injuries in pitchers may not be caused by the curveball mechanics. Further evaluation of adolescent and adult baseball pitchers is warranted to help determine and subsequently reduce the risk of injury.

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.

Biomechanical comparison of patellar tendon repairs in a cadaver model: an evaluation of gap formation at the repair site with cyclic loading.

Background Ruptures of the patellar tendon are rare injuries. Surgical treatment for this injury is mandatory. Hypothesis Gap formation does not differ between the three patellar tendon repair techniques. Study Design Controlled laboratory study. Methods Twelve fresh-frozen cadaveric knees were used to compare three techniques of patellar tendon repairs. The standard suture repair used two Krackow sutures placed in the avulsed patellar tendon, passed through transpatellar drill holes, and secured with the knee in 30° of flexion. In the second group, suture repair was augmented with a No. 5 Ethibond suture. In the third group, suture repair was augmented with a 2.0 Dall-Miles cable. Testing was performed with the specimens mounted to a custom knee jig with the tibia free, simulating the knee moment of a 70-kg person. Each knee was then cycled 250 times at 0.25 Hz. Results Gap formation across the standard suture repair averaged 7.3 mm; across the suture augmentation and cable augmentation groups it averaged 4.9 mm and 3.5 mm, respectively. Conclusions Augmentation of patellar tendon avulsions can decrease gap formation at the repair site, allowing early mobilization. Clinical Relevance Gap formation seen in repair without augmentation could lead to clinical failure with resultant patella alta and extensor mechanism lag.

AOSSM Early Sport Specialization Consensus Statement.

Background: Early sport specialization is not a requirement for success at the highest levels of competition and is believed to be unhealthy physically and mentally for young athletes. It also discourages unstructured free play, which has many benefits. Purpose: To review the available evidence on early sports specialization and identify areas where scientific data are lacking. Study Design: Think tank, roundtable discussion. Results: The primary outcome of this think tank was that there is no evidence that young children will benefit from early sport specialization in the majority of sports. They are subject to overuse injury and burnout from concentrated activity. Early multisport participation will not deter young athletes from long-term competitive athletic success. Conclusion: Youth advocates, parents, clinicians, and coaches need to work together with the sport governing bodies to ensure healthy environments for play and competition that do not create long-term health issues yet support athletic competition at the highest level desired.

Osteoarthritis classification scales: Interobserver reliability and arthroscopic correlation

BACKGROUND Osteoarthritis 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. METHODS As 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. RESULTS Overall, 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. CONCLUSIONS The 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. LEVEL OF EVIDENCE Diagnostic Level I. See Instructions for Authors for a complete description of levels of evidence.

Outcomes of Autologous Chondrocyte Implantation in Study of the Treatment of Articular Repair (STAR) Patients With Osteochondritis Dissecans

Background: This is an analysis of the prospective Study of the Treatment of Articular Repair (STAR) to evaluate the effectiveness of autologous chondrocyte implantation (ACI) in a subset of adult patients with osteochondritis dissecans (OCD) knee lesions. Hypothesis: Autologous chondrocyte implantation can improve clinical outcomes in patients with at least 1 chronic OCD lesion of the knee who failed a previous non-ACI cartilage repair treatment. Study Design: Case series; Level of evidence, 4. Methods: Forty patients with at least one failed non-ACI treatment for an OCD knee lesion received ACI in a multicenter study. The modified Cincinnati Knee Rating System, the Knee injury and Osteoarthritis Outcome Score (KOOS), and the Short-Form 36 Health Survey (SF-36) were used to assess patient outcomes at baseline and periodically to 48 months. Treatment failures, serious adverse events, and subsequent surgical procedures were recorded. Results: Thirty-two (80%) patients completed the 48-month study. Autologous chondrocyte implantation treatment was successful in 85% of patients. Mean (± standard deviation) overall knee condition score (modified Cincinnati) was 3.1 ± 1.1 at baseline and 6.8 ± 2.0 at month 48. Clinically and statistically significant (P < .001) mean improvements from baseline to month 48 for the KOOS were as follows: 51.5 to 79.5 (pain), 54.8 to 77.9 (symptoms), 27.5 to 63.6 (sports and recreation ability), 63.5 to 86.7 (activities of daily living), and 21.9 to 59.6 (knee-related quality of life). The mean improvement (P < .001) in overall health assessed by the SF-36 was 35.4 to 45.5. Thirty-five percent (n = 14/40) of patients had a subsequent surgical procedure, most frequently debridement of the cartilage lesion. Treatment failure occurred in 6 of 32 (19%) patients. Conclusion: Patients with OCD of the knee had statistically significant pain reduction and functional improvement for up to 48 months after ACI, despite the complexity and severity of the osteochondral lesions.

Multirater Agreement of the Causes of Anterior Cruciate Ligament Reconstruction Failure A Radiographic and Video Analysis of the MARS Cohort

Background: Anterior cruciate ligament (ACL) reconstruction failure occurs in up to 10% of cases. Technical errors are considered the most common cause of graft failure despite the absence of validated studies. Limited data are available regarding the agreement among orthopaedic surgeons regarding the causes of primary ACL reconstruction failure and accuracy of graft tunnel placement. Hypothesis: Experienced knee surgeons have a high level of interobserver reliability in the agreement about the causes of primary ACL reconstruction failure, anatomic graft characteristics, and tunnel placement. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Twenty cases of revision ACL reconstruction were randomly selected from the Multicenter ACL Revision Study (MARS) database. Each case included the patient’s history, standardized radiographs, and a concise 30-second arthroscopic video taken at the time of revision demonstrating the graft remnant and location of the tunnel apertures. All 20 cases were reviewed by 10 MARS surgeons not involved with the primary surgery. Each surgeon completed a 2-part questionnaire dealing with each surgeon’s training and practice, as well as the placement of the femoral and tibial tunnels, condition of the primary graft, and the surgeon’s opinion as to the causes of graft failure. Interrater agreement was determined for each question with the kappa coefficient and the prevalence-adjusted, bias-adjusted kappa (PABAK). Results: The 10 reviewers have been in practice an average of 14 years and have performed at least 25 ACL reconstructions per year, and 9 were fellowship trained in sports medicine. There was wide variability in agreement among knee experts as to the specific causes of ACL graft failure. When participants were specifically asked about technical error as the cause for failure, interobserver agreement was only slight (PABAK = 0.26). There was fair overall agreement on ideal femoral tunnel placement (PABAK = 0.55) but only slight agreement on whether a femoral tunnel was too anterior (PABAK = 0.24) and fair agreement on whether it was too vertical (PABAK = 0.46). There was poor overall agreement for ideal tibial tunnel placement (PABAK = 0.17). Conclusion: This study suggests that more objective criteria are needed to accurately determine the causes of primary ACL graft failure as well as the ideal femoral and tibial tunnel placement in patients undergoing revision ACL reconstruction.

Short-Term Recovery After Anterior Cruciate Ligament Reconstruction: A Prospective Comparison of Three Autografts

Sixty-four patients with three different autografts were prospectively evaluated following anterior cruciate ligament (ACL) reconstruction for motion return, thigh girth, quadriceps activity, assistive device usage, and duration of pain medication usage. The quadriceps tendon group achieved knee extension sooner than the patellar tendon group. The hamstring group used assistive devices for less time than the patellar tendon group. The quadriceps group required less pain medication than either of the groups. There are significant differences in short-term pain medication requirements and restoration of function among patients following ACL reconstruction using different autografts.