Sverre Løken

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.

Low back pain among endurance athletes with and without specific back loading--a cross-sectional survey of cross-country skiers, rowers, orienteerers, and nonathletic controls.

Study Design. Cross-sectional survey among athletes competing at the national elite level in cross-country skiing, rowing, and orienteering, as well as a matched nonathletic control group. Objective. To compare the prevalence of symptoms of low back pain between endurance sports with different loading characteristics on the lumbar region: cross-country skiing, rowing, and orienteering, as well as a nonathletic control group. Summary of Background Data. Although it is claimed that back pain is a frequent problem in endurance sports loading the lower spine such as rowing or cross-country skiing, the prevalence of low back problems in such sports has not been compared with relevant control groups. Methods. Self-reported questionnaire on low back pain adapted for sports based on standardized Nordic questionnaires for musculoskeletal symptoms. Responders were 257 cross-country skiers (response rate: 100%), 199 rowers (99.5%), and 278 orienteerers (99.3%), and 197 control subjects (66%). Results. Low back pain was reported to be somewhat more common among cross-country skiers and rowers than orienteerers and nonathletic controls. The prevalence among cross-country skiers of reported low back pain ever (65.4%) and low back pain during the previous 12 months (63.0%) was higher than nonathletic controls (OR [95% CI]: 1.94 [1.29–2.92]). Rowers (25.6%) reported missing training because of low back pain more frequently than orienteerers did (13.7%, OR: 2.16 [1.25–3.74]). The athletes reported more low back pain during periods when training and competition load was higher, and cross-country skiers more frequently reported having low back problems using classic than freestyle skiing techniques. Conclusions. Low back pain appears to be somewhat more common in endurance sports that specifically load the low back during training and competition. The relationship between seasonal training patterns and specific skiing techniques indicate that there is a relationship between low back pain and the specific loading patterns of skiing and rowing.

A Randomized Multicenter Trial Comparing Autologous Chondrocyte Implantation with Microfracture: Long-term Follow-up at 14 to 15 Years.

BACKGROUND The management of cartilage and osteochondral lesions in the knee remains problematic and controversial. Our group reported the 2-year and 5-year results of a randomized controlled trial comparing autologous chondrocyte implantation (ACI) and microfracture in patients with focal femoral cartilage injuries. The objective of the present study was to report the long-term results. METHODS Eighty patients with a single symptomatic chronic cartilage defect on the femoral condyle without general osteoarthritis were included in the study at the time of the index operation (January 1999 to February 2000). We used the International Cartilage Repair Society (ICRS), Lysholm, Short Form-36 (SF-36), and Tegner forms to collect data at the time of inclusion and at follow-up evaluations. Standing weight-bearing radiographs were evaluated for evidence of osteoarthritis according to the method described by Kellgren and Lawrence. For the long-term follow-up in 2014, we used the Synaflexer frame to standardize the radiographs. The operation was considered to have failed if a reoperation was performed because of symptoms from a lack of healing of the treated defect. RESULTS At the long-term follow-up evaluation, no significant differences between the treatment groups were detected with respect to the results on the clinical scoring systems. At the 15-year evaluation, there were 17 failures in the ACI group compared with 13 in the microfracture group. We observed that more total knee replacements were needed in the ACI group than in the microfracture group (6 compared with 3). The surviving patients in both groups, i.e., those who had not had a failure, had significant improvement in the clinical scores compared with baseline. Fifty-seven percent of the surviving patients in the ACI group and 48% of such patients in the microfracture group had radiographic evidence of early osteoarthritis (a Kellgren and Lawrence grade of ≥2); the difference was not significant. CONCLUSIONS The survivors in both groups improved their clinical scores in the short, medium, and long-term evaluations, and no significant difference between the groups was found at the long-term follow-up. The risk of treatment failure and the frequency of radiographic osteoarthritis are problematic. Our findings raise serious concerns regarding the efficacy of these procedures in delaying osteoarthritis and preventing further surgery. Continued basic and clinical research is needed in this field. LEVEL OF EVIDENCE Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Persistence of Collagen Type II Synthesis and Secretion in Rapidly Proliferating Human Articular Chondrocytes In Vitro

Articular chondrocytes (AC) expanded in vitro for tissue engineering rapidly turn off collagen type II (COL2) synthesis. We wanted to inhibit this process sufficiently to obtain therapeutically useful numbers of AC without losing COL2 synthesis. To this end, AC were expanded on their own extracellular matrix (ECM) in structures designated chondrocytes in autologous ECM (CA-ECM). Here, AC maintained a rounded shape and proliferated rapidly. After 13-15 days in culture, 40 x 10(6) cells (median) could be obtained from a cartilage biopsy. Real-time RT-PCR showed a reduced, but persistent, production of COL2A1 mRNA at this time. Flow cytometry showed high levels of intracellular COL2, and immunogold electron microscopy showed high density of well-organized COL2 fibrils in newly synthesized ECM. Interestingly, high levels of COL1A1 mRNA and intracellular protein were detected, but no COL1 was found in the ECM. The slow loss of COL2A1 mRNA was paralleled by a loss of the COL2 regulating transcription factor SOX9 mRNA. Chromatin immunoprecipitation assays could not identify epigenetic histone modifications that would explain the observed changes in COL2 synthesis. Thus, the CA-ECM strategy allows AC to proliferate to clinically useful numbers while maintaining COL2 synthesis and secretion. This strategy may improve tissue engineering of joint surfaces.

Articular cartilage defects in a rabbit model, retention rate of periosteal flap cover.

Background A periosteal flap is frequently used in procedures involving repair of articular cartilage defects. Hypertrophy of the repair tissue, probably from a retained periosteum, is a clinical problem but not much is known about this issue. The objective of the present experimental study was to investigate the retention rate of periosteal flaps with respect to various postoperative mobilization regimes and the introduction of bone marrow elements underneath the flap. Method We created a chondral lesion (diameter 4 mm) in both patellas of 18 New Zealand white rabbits. The subchondral bone was left intact in one knee. In the other, the bone plate was perforated, allowing bone marrow elements to enter the defect. All defects were covered with a periosteal flap, sutured and glued to the rim of the cartilage defect. Postoperatively, the rabbits were allocated to one of three groups: A. rehabilitation in cages for 4 days, then killed; B. rehabilitation in cages for 7 days, then free activity on the floor of a 10 m2 room until the end of the second week, then killed; C. rehabilitation in cages for 2 weeks, then killed. Results 16 of 23 periosteal flaps became detached within 2 weeks (one knee was excluded because of clinical signs of infection), with no difference in the retention rate with respect to mobilization regime or established access to bone marrow elements in the defect. The periosteum still served as a cover of the defect in 10 of 12 knees at day 4. This figure decreased to 7 of 23 knees at day 14. Conclusion Our study is the first to document the retention rate of periosteal flaps in a rabbit model. The low retention rate observed may explain why periosteal hypertrophy is not reported in experimental studies where the periosteal flap is sutured to the cartilage rim.

Demographics and Injuries Associated With Knee Dislocation: A Prospective Review of 303 Patients:

Background: Information on the incidence, injury mechanisms, ligament injury patterns, and associated injuries of knee dislocations is lacking in the literature. There is a need to characterize ligament injury patterns and associated injuries in knee dislocations to avoid missing common associated diagnoses and to plan surgical treatment. Purpose: To evaluate patient demographics, ligament injury patterns and associated injury patterns, and associated injuries in patients with knee dislocation. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 303 patients with knee dislocations treated at a single level 1 trauma center were followed prospectively. Injury mechanism; ligament injury patterns; associated neurovascular, meniscal, and cartilage injuries; and surgical complications were recorded. The Schenck knee dislocation classification was used to classify the ligament injury patterns. Results: The mean age at injury was 37.8 ± 15.3 years. Of the 303 patients included, 65% were male and 35% were female. There was an equal distribution of high-energy and low-energy injuries. Injury to 3 major ligaments was the most common, with Schenck classification type KD III-M constituting 52.4% of the injuries and KD III-L comprising 28.1%. Meniscal injuries and cartilage injuries occurred in 37.3% and 28.3% of patients, respectively. Patients with acute injuries had significantly lower odds of a cartilage injury than those with chronic injuries (odds ratio [OR], 0.28; 95% CI, 0.15-0.50; P < .001). Peroneal nerve injuries were recorded in 19.2% of patients (10.9% partial and 8.3% complete deficit), while vascular injuries were recorded in 5%. The odds of having a common peroneal nerve injury were 42 times greater (P < .001) among those with posterolateral corner injury (KD III-L) than those without. The odds for popliteal artery injury were 9 times greater (P = .001) among those with KD III-L injuries than other ligament injury types. Conclusion: Medial-sided bicruciate injuries were the most common injury pattern in knee dislocations. Cartilage injuries were common in chronically treated patients. There was a significant risk of peroneal nerve injury with lateral-sided injuries.

No degeneration found in focal cartilage defects evaluated with dGEMRIC at 12-year follow-up

Background and purpose — The natural history of focal cartilage defects (FCDs) is still unresolved, as is the long-term cartilage quality after cartilage surgery. It has been suggested that delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is a biomarker of early OA. We aimed to quantitatively evaluate the articular cartilage in knees with FCDs, 12 years after arthroscopic diagnosis. Patients and methods — We included 21 patients from a cohort of patients with knee pain who underwent arthroscopy in 1999. Patients with a full-thickness cartilage defect, stable knees, and at least 50% of both their menisci intact at baseline were eligible. 10 patients had cartilage repair performed at baseline (microfracture or autologous chondrocyte implantation), whereas 11 patients had either no additional surgery or simple debridement performed. Mean follow-up time was 12 (10–13) years. The morphology and biochemical features were evaluated with dGEMRIC and T2 mapping. Standing radiographs for Kellgren and Lawrence (K&L) classification of osteoarthritis (OA) were obtained. Knee function was assessed with VAS, Tegner, Lysholm, and KOOS. Results — The dGEMRIC showed varying results but, overall, no increased degeneration of the injured knees. Degenerative changes (K&L above 0) were, however, evident in 13 of the 21 knees. Interpretation — The natural history of untreated FCDs shows large dGEMRIC variations, as does the knee articular cartilage of surgically treated patients. In this study, radiographic OA changes did not correlate with cartilage quality, as assessed with dGEMRIC.

Radiographic Identification of Arthroscopically Relevant Acetabular Structures

Background: The anatomy of the acetabulum has been described extensively in the literature, but radiographic acetabular guidelines have not been well established. This study provides a radiographic map of acetabular landmarks in the hip. Purpose/Hypothesis: The purpose of this study was to quantify the precise radiographic location of arthroscopic landmarks around the acetabulum. The hypothesis was that their locations were reproducible despite variability in the anatomy and positioning of pelvic specimens. Study Design: Descriptive laboratory study. Methods: Ten fresh-frozen cadaveric specimens were dissected, and radio-opaque hardware was placed for each landmark of interest. Anteroposterior (AP) and false-profile radiographs were obtained, and measurements were taken using a digital picture archiving and communication system. Results: On AP radiographs, the direct and indirect heads of the rectus femoris were a mean 48.2 ± 4.6 mm and 44.7 ± 4.3 mm proximal to the teardrop line, respectively. The mean radiographic distance between their insertions was 5.0 ± 3.4 mm. Moreover, the anterior inferior iliac spine was a mean 11.5 ± 3.8 mm from the acetabular rim. On false-profile radiographs, the mean distance between the direct and indirect heads of the rectus femoris was 31.4 ± 6.2 mm. The mean distance between the superior margin of the anterior labral sulcus (the psoas-u) and the midpoint of the transverse acetabular ligament was 41.0 ± 5.7 mm. Additionally, the direct and indirect heads of the rectus femoris corresponded to the 2:30 and 1:30 locations on the acetabular clockface, respectively. The midpoint of the transverse acetabular ligament was located at 7 o’clock on the clockface. Conclusion: The most important finding of this study, determined by quantitative measurements, was that the described surgical landmarks had reliable locations on radiographs. Distances between landmarks as well as distances between landmarks and reference lines were reproducible in both AP and false-profile views. Clinical Relevance: An understanding of how acetabular structures present on radiographs could lead to more accurate portal and hardware placement intraoperatively during arthroscopic surgery as well as better preoperative and postoperative assessments.

Radiographic Identification of Arthroscopically Relevant Proximal Femoral Structures

Background: Anatomic landmarks located on the proximal femur have only recently been defined, and there is a lack of radiographic guidelines for their locations presented in the literature. With the confident identification of these landmarks, radiographs could provide more assistance in preoperative evaluations, intraoperative guidance, and postoperative assessments. Purpose: To quantify the radiographic locations of endoscopic landmarks of the proximal femur. Study Design: Descriptive laboratory study. Methods: Ten cadaveric specimens were dissected, and radio-opaque hardware was placed for each landmark of interest. Radiographs were obtained and measurements recorded in anteroposterior (AP) and Dunn 45° views. Results: In the AP view, the gluteus medius insertion was located a mean 12.9 ± 2.4 mm and 34.7 ± 5.1 mm from the piriformis fossa and vastus tubercle, respectively. The piriformis fossa was a mean 14.8 ± 5.9 mm and 4.9 ± 1.9 mm from the anterior and posterior tips of the greater trochanter, respectively. The anterior and posterior tips of the greater trochanter were a mean 14.8 ± 5.1 mm from each other. In the Dunn 45° view, the piriformis fossa was a mean 13.3 ± 2.0 mm, and the vastus tubercle was a mean 21.5 ± 6.0 mm, from the gluteus medius insertion. Moreover, the vastus tubercle was a mean 33.5 ± 6.4 mm from the anterior tip of the greater trochanter and 31.6 ± 8.5 mm from the posterior tip of the greater trochanter. Conclusion: In spite of the variation in cadaveric sizes, quantitative descriptions of endoscopic landmarks were reproducible in clinical views. Clinical Relevance: A detailed understanding of how the described landmarks present radiographically is relevant to preoperative planning, intraoperative evaluations, and postoperative assessments.