Asbjørn Årøen

Articular Cartilage Lesions in 993 Consecutive Knee Arthroscopies

Background Traumatic articular cartilage injuries heal poorly and may lead to development of osteoarthritis at a young age. This study estimates the number of patients who may benefit from one of the surgical methods of cartilage repair. Methods All patients undergoing knee arthroscopy during a 6-month period at three collaborating hospitals were consecutively evaluated according to the International Cartilage Repair Society (ICRS) knee form. The material consists of 993 consecutive knee arthroscopies in patients with median age of 35 years. Results Preoperative radiographs demonstrated degenerative changes in 13% of the knees. Articular cartilage pathology was found in 66% and a localized cartilage defect was found in 20% of the knees. A localized full-thickness cartilage lesion (ICRS grade 3 and 4) was observed in 11% of the knees. Of the localized full-thickness lesions, 55% (6% of all knees) had a size above 2 cm2. Conclusion Eleven percent of all knee arthroscopies show cartilage defects that may be suitable for cartilage repair procedures. However, the natural history of these lesions and the number of patients that will benefit from a cartilage repair procedure are so far unknown.

Focal Cartilage Defects in the Knee Impair Quality of Life as Much as Severe Osteoarthritis A Comparison of Knee Injury and Osteoarthritis Outcome Score in 4 Patient Categories Scheduled for Knee Surgery

Background Patients with focal cartilage defects in the knee may suffer from both pain and functional impairment. Treatment options are often insufficient. It is not known, however, to what extent their complaints affect quality of life, compared with other knee disorders. Knee Injury and Osteoarthritis Outcome Score (KOOS) is a validated global knee score suitable for comparison of patients with knee complaints attributable to different causes. Hypothesis Complaints because of localized cartilage defects in the knee reduce quality of life measured by KOOS to a different extent than those due to anterior cruciate ligament deficiency and osteoarthritis, when comparing patients within the working population scheduled for surgery. Study Design Cross-sectional study; Level of evidence, 3. Methods Previously registered KOOS baseline data on patients enrolled in different knee treatment studies were included in the present study; the patients were 18 to 67 years of age (working population) at data registration. The different patient categories were (1) patients with knee osteoarthritis enrolled for knee arthroplasty, (2) patients with knee osteoarthritis enrolled for osteotomies around the knee, (3) patients with focal cartilage lesions enrolled for cartilage repair, and (4) patients with anterior cruciate ligament—deficient knees enrolled for anterior cruciate ligament reconstruction. The KOOS subscale quality of life was the main parameter for comparison of complaints. Results At preoperative baseline, patients with focal cartilage defects in the knee scored 27.5 on the KOOS subscale quality of life, not significantly different from the 28.8 and 27.2 in the patients with osteoarthritis enrolled for knee osteotomies and arthroplasties, respectively. For all the subscales of KOOS, the cartilage patients scored significantly lower than the patients with anterior cruciate ligament deficiency. Conclusion Patients with focal cartilage lesions have major problems with pain and functional impairment. Their complaints are worse than those of patients with anterior cruciate ligament—deficient knees, and quality of life is affected to the same extent as in patients scheduled for knee replacement.

Effect of Meniscal and Focal Cartilage Lesions on Patient-Reported Outcome After Anterior Cruciate Ligament Reconstruction A Nationwide Cohort Study From Norway and Sweden of 8476 Patients With 2-Year Follow-up

Background: The effect of concomitant intra-articular injury on patient-reported outcome after anterior cruciate ligament (ACL) reconstruction is debated. Purpose: To evaluate the effect of meniscal and articular cartilage lesions on patient-reported outcome 2 years after ACL reconstruction. Study Design: Cohort study (prognosis); Level of evidence, 2. Methods: The study included all patients with primary, unilateral ACL reconstruction registered in the Norwegian and the Swedish National Knee Ligament Registry from 2005 through 2008 who had completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) Knee-Related Quality of Life subscale at a 2-year follow-up (mean ± SD, 2.1 ± 0.2 years) after surgery (n = 8476). Multiple linear regression analyses were used to evaluate the associations between each KOOS subscale (Pain, Other Symptoms, Activities of Daily Living, Sport and Recreation Function, Knee-Related Quality of Life) as the measure for patient-reported outcome and meniscal and cartilage lesions. Results: A total of 3674 (43%) patients had meniscal lesion(s), 1671 (20%) had partial-thickness (International Cartilage Repair Society [ICRS] grades 1-2) cartilage lesion(s), and 551 (7%) had full-thickness (ICRS grades 3-4) cartilage lesion(s). Multiple linear regression analyses detected no significant associations between meniscal lesions or partial-thickness cartilage lesions and the scores in any of the KOOS subscales at the 2-year follow-up. Full-thickness cartilage lesions were significantly associated with decreased scores in all of the KOOS subscales. Conclusion: Patients with concomitant full-thickness cartilage lesions reported worse outcome in all of the KOOS subscales compared with patients without cartilage lesions 2 years after ACL reconstruction. Meniscal lesions and partial-thickness cartilage lesions did not impair patient-reported outcome 2 years after ACL reconstruction.

Kinematic Analysis of the Posterior Cruciate Ligament, Part 2 A Comparison of Anatomic Single- Versus Double-Bundle Reconstruction

Background: A more thorough understanding of the posterior cruciate ligament (PCL) has led to an increase in awareness and treatment of complex PCL injuries. Controversy exists about whether PCL reconstruction (PCLR) using an anatomic single-bundle (aSB) or anatomic double-bundle (aDB) technique is the most effective. Hypothesis: An aDB PCLR provides significantly better anterior-posterior and rotatory knee stability compared with an aSB PCLR and more closely recreates normal knee kinematics. Study Design: Controlled laboratory study. Methods: A total of 18 match-paired, cadaveric knees (mean age, 54.8 years; range, 51-59 years; 5 male and 4 female pairs) were used to evaluate the kinematics of an intact PCL, an aSB and aDB PCLR, and a complete sectioned PCL. A 6 degrees of freedom robotic system was used to assess knee stability with a 134-N applied posterior tibial load, 5-N·m external and internal rotation torques, 10-N·m valgus and varus rotation torques, and a coupled 100-N posterior tibial load and 5-N·m external rotation torque at 0°, 15°, 30°, 45°, 60°, 75°, 90°, 105°, and 120°. Results: The aDB PCLR had significantly less posterior translation than the aSB PCLR at all flexion angles of 15° and greater. The largest difference in posterior translation was seen at 105° of flexion, where the aSB PCLR had 5.3 mm (P = .017) more posterior translation than the aDB PCLR. The aDB PCLR also had significantly less internal rotation than the aSB PCLR at all tested angles of 90° and greater. Neither reconstruction was able to fully restore native knee kinematics. Conclusion: An aDB PCLR more closely approximated native knee kinematics when compared with an aSB PCLR. Specifically, the aDB PCLR demonstrated significantly more restraint to posterior translation at flexion angles between 15° and 120° and less internal rotational laxity at high flexion angles 90° to 120°. Clinical Relevance: Comparison of the 2 reconstruction techniques illustrates the time-zero kinematic advantage imparted by the addition of the posteromedial bundle reconstruction. The benefit is most pertinent for resistance to posterior translation across a full range of flexion and rotational stability beyond 90° of knee flexion.

Kinematic Analysis of the Posterior Cruciate Ligament, Part 1 The Individual and Collective Function of the Anterolateral and Posteromedial Bundles

Background: The posterior cruciate ligament (PCL) is composed of 2 functional bundles and has an essential role in knee function and stability. There is, however, a limited understanding of the role of each individual bundle through the full range of knee flexion. Hypothesis: Both bundles provide restraint to posterior tibial translation across a full range of knee flexion. At higher angles of knee flexion (>90°), the intact PCL also imparts significant rotational stability. Study Design: Controlled laboratory study. Methods: Twenty matched-paired, human cadaveric knees (mean age, 55.2 years; range, 51-59 years; 6 male and 4 female pairs) were used to evaluate the kinematics of an intact, anterolateral bundle (ALB) sectioned, posteromedial bundle (PMB) sectioned, and complete PCL sectioned knee. A 6 degree of freedom robotic system was used to assess knee stability with an applied 134-N posterior tibial load, 5-N·m external and internal rotation torques, 10-N·m valgus and varus torques, and a coupled 100-N posterior tibial load and 5-N external rotation torque at 0°, 15°, 30°, 45°, 60°, 75°, 90°, 105°, and 120°. Results: All sectioned states had significant increases compared with intact in posterior translation, internal rotation, and external rotation at all tested flexion angles, with the exception of the ALB sectioned state at 75° of flexion for external rotation. The significant increases (mean ± standard deviation) in posterior translation during a 134-N posterior tibial load at 90° of flexion were 0.9 ± 0.6 mm, 2.6 ± 1.8 mm, and 11.7 ± 4.0 mm for the PMB, ALB, and complete PCL sectioned states, respectively, compared with the intact state. The largest significant increases in internal rotation were in the PMB and complete PCL sectioned states at 105° of flexion, 1.3° ± 1.0° and 2.8° ± 2.1°, respectively. Conclusion: Both the ALB and the PMB assume a significant role in resisting posterior tibial translation, at all flexion angles, suggesting a codominant relationship. The PCL provided a significant constraint to internal rotation beyond 90° of flexion. Clinical Relevance: This information broadens the understanding of native knee kinematics and provides a template for the evaluation of single- and double-bundle PCL reconstructions.

Fractures in Children: Epidemiology and Activity-specific Fracture Rates

BACKGROUND Approximately one-third of pediatric fractures occur during sport or recreational activity. In this paper, we investigate the incidence and causes of pediatric fractures in our region and quantify the fracture rate per exposure time for the most common sport and recreational activities. METHODS We prospectively evaluated all children younger than sixteen years who presented to our institution with a new fracture within a twelve-month period. Exposure time to the most common childhood activities was measured by means of interviewing random parents from the study population. The main outcome measures were the annual fracture incidence in the population and fracture rates per 10,000 hours of exposure to various sports and recreational activities. RESULTS A total of 1403 fractures were included. The overall annual incidence was 180.1 fractures per 10,000 children younger than sixteen years. The distal part of the radius was most often fractured (436 fractures, 31.1%). Snowboarding was associated with the highest activity-specific fracture rate, estimated to be 1.9 (95% confidence interval [CI], 1.16 to 2.60) fractures per 10,000 hours of exposure. In comparison, the fracture rate per 10,000 hours of exposure was 0.79 (CI, 0.42 to 1.09) for handball, 0.44 (CI, 0.35 to 0.52) for soccer, and 0.35 (CI, 0.23 to 0.47) for trampolining. CONCLUSIONS The distal part of the radius is the most common fracture site in childhood. Fracture rates differ between various physical activities. The fracture rate for snowboarding was four times higher compared with that for other common childhood sport and recreational activities in our region.

Knee Cartilage Defect Patients Enrolled in Randomized Controlled Trials Are Not Representative of Patients in Orthopedic Practice.

Objective: Knee cartilage defects represent a socioeconomic burden and may cause lifelong disability. Studies have shown that cartilage defects are detected in approximately 60% of knee arthroscopies. In clinical trials, the majority of these patients are excluded. This study investigates whether patients included in randomized controlled trials (RCTs) represent a selected group compared to general cartilage patients. Design: Published randomized clinical trials on cartilage repair studies were identified (May 2009) and analyzed to define common inclusion criteria that in turn were applied to all patients submitted to our cartilage repair center during 2008. Patient-administered Lysholm knee score was used to evaluate functional level at referral. In addition, previous surgery and size and localization of cartilage defects were recorded. Results: Common inclusion criteria in the referred patients and patients included in the published RCTs were single femoral condyle lesion, age range 18 to 40 years, and size of lesion range 3.2 to 4.0 cm2. Six of 137 referred patients matched all the 7 RCTs. Previous cartilage repair and multiple lesions were associated with decreased Lysholm score (P < 0.002). Lysholm score was independent of age, gender, and time of symptoms from the defect. Conclusion: The heterogeneity of the referred cartilage patients and the variation in inclusion criteria in the RCTs may question whether RCTs actually represent the general cartilage patients. The present study suggests that results from published RCTs may not be representative of the gross cartilage population.

Effect of Gender and Sports on the Risk of Full-Thickness Articular Cartilage Lesions in Anterior Cruciate Ligament–Injured Knees A Nationwide Cohort Study From Sweden and Norway of 15 783 Patients

Background: The presence of an articular cartilage lesion in anterior cruciate ligament–injured knees is considered a predictor of osteoarthritis. Purpose: This study was undertaken to evaluate risk factors for full-thickness articular cartilage lesions in anterior cruciate ligament–injured knees, in particular the role of gender and the sport causing the initial injury. Study Design: Cohort study (prognosis); Level of evidence, 2. Methods: Primary unilateral anterior cruciate ligament reconstructions prospectively registered in the Swedish and the Norwegian National Knee Ligament Registry during 2005 through 2008 were included (N = 15 783). Logistic regression analyses were used to evaluate risk factors for cartilage lesions. Results: A total of 1012 patients (6.4%) had full-thickness cartilage lesions. The median time from injury to surgery was 9 months (range, 0 days-521 months). Male patients had an increased odds of full-thickness cartilage lesions compared with females (odds ratio = 1.22; 95% confidence interval, 1.04-1.42). In males, team handball had an increase in the odds of full-thickness cartilage lesions compared with soccer (odds ratio = 2.36; 95% confidence interval, 1.33-4.19). Among female patients, no sport investigated showed a significant decrease or increase in the odds of full-thickness cartilage lesions. The odds of a full-thickness cartilage lesion increased by 1.006 (95% confidence interval, 1.005-1.008) for each month elapsed from time of injury until anterior cruciate ligament reconstruction when all patients were considered, while time from injury to surgery did not affect the odds significantly in those patients reconstructed within 1 year of injury (odds ratio = 0.98; 95% confidence interval, 0.95-1.02). Previous surgery increased the odds of having a full-thickness cartilage lesion (odds ratio = 1.40; 95% confidence interval, 1.21-1.63). One year of increasing patient age also increased the odds (odds ratio = 1.05; 95% confidence interval, 1.05-1.06). Conclusion: Male gender is associated with an increased risk of full-thickness articular cartilage lesions in anterior cruciate ligament–injured knees. Male team handball players had an increased risk of full-thickness lesions. No other sports investigated were found to have significant effect on the risk in either gender. Furthermore, age, previous surgery, and time from injury to surgery exceeding 12 months are risk factors for full-thickness cartilage lesions.

The Feasibility of a 3-Month Active Rehabilitation Program for Patients With Knee Full-Thickness Articular Cartilage Lesions: The Oslo Cartilage Active Rehabilitation and Education Study

STUDY DESIGN Case series. OBJECTIVES To evaluate the feasibility of an active rehabilitation program for patients with knee full-thickness articular cartilage lesions. BACKGROUND No studies have yet evaluated the effect of active rehabilitation in patients with knee full-thickness articular cartilage lesions or compared the effects of active rehabilitation to those of surgical interventions. As an initial step, the feasibility of such a program needs to be described. METHODS Forty-eight patients with a knee full-thickness articular cartilage lesion and a Lysholm score below 75 participated in a 3-month active rehabilitation program consisting of cardiovascular training, knee and hip progressive resistance training, and neuromuscular training. Feasibility was determined by monitoring adherence to the program, clinical changes in knee function, load progression, and adverse events. Patients were tested before and after completing the rehabilitation program by using patient-reported outcomes (Knee injury and Osteoarthritis Outcome Score, International Knee Documentation Committee Subjective Knee Evaluation Form 2000) and isokinetic muscle strength and hop tests. To monitor adherence, load progression, and adverse events, patients responded to an online survey and kept training diaries. RESULTS The average adherence rate to the rehabilitation program was 83%. Four patients (9%) showed adverse events, as they could not perform the exercises due to pain and effusion. Significant and clinically meaningful improvement was found, based on changes on the International Knee Documentation Committee Subjective Knee Evaluation Form 2000, the Knee injury and Osteoarthritis Outcome Score quality of life subscale, isokinetic muscle strength, and hop performance (P<.05), with small to large effect sizes (standardized response mean, 0.3-1.22). CONCLUSION The combination of a high adherence rate, clinically meaningful changes, and positive load progression and the occurrence of only a few adverse events support the potential usefulness of this program for patients with knee full-thickness cartilage lesions. This study was registered with the public trial registry ClinicalTrials.gov (NCT00885729). LEVEL OF EVIDENCE Therapy, level 4.

Surgical Site Infections in Orthopaedic Surgery Demonstrate Clones Similar to Those in Orthopaedic Staphylococcus aureus Nasal Carriers

BACKGROUND Staphylococcus aureus is the main microbial pathogen in orthopaedic infections, and it adds considerable extra costs to the national health-care system each year. Nasal carriers of Staphylococcus aureus have an increased risk of invasive disease, including surgical site infection. The purpose of the present study was to investigate whether the Staphylococcus aureus carrier clones found in patients undergoing elective orthopaedic surgery were the same as the clones found in isolates from orthopaedic patients with Staphylococcus aureus surgical site infections. METHODS Patients admitted for elective orthopaedic surgery underwent nasal cultures for Staphylococcus aureus. Further, orthopaedic patients with a deep surgical site infection caused by Staphylococcus aureus were characterized using the same genotyping methods: multilocus sequence typing and staphylococcal protein A typing. RESULTS Multilocus sequence typing revealed a large number of genotypes in the two populations. However, 85% of nasal carriers and 90% of surgical site infection isolates could be classified into the same four multilocus sequence typing clonal complexes. The risk of Staphylococcus aureus surgical site infection in nasal carriers compared with non-carriers was 5.8 times higher (95% confidence interval, 1.5 to 23.1 times). Of the nasal carriers, 6.3% (95% confidence interval, 1.7% to 10.9% [seven of 111 patients]) developed a deep Staphylococcus aureus surgical site infection, and all but one patient had identical genotypes in the nasal and surgical site infection isolates. CONCLUSIONS Staphylococcus aureus isolates from nasal carriers and patients with surgical site infection clustered into the same few multilocus sequence typing clonal complexes. This finding confirms the existence of some commonly occurring Staphylococcus aureus clones in different population groups within a geographically restricted area. The almost complete individual concordance between Staphylococcus aureus genotypes in carriers who developed a deep surgical site infection strongly supports transmission from the nose, skin surfaces, and other endogenous body regions as a possible route. CLINICAL RELEVANCE Surgical site infections might be more frequently caused by endogenous transmission than was previously assumed. Perioperative preventive efforts must focus more on this route to further decrease the risk of postoperative orthopaedic infections.