Stig Heir

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.

Injuries among male and female World Cup alpine skiers

Background: Limited knowledge exists on injuries among professional alpine skiers. Objective: To describe the risk of injury and the injury pattern among competitive World Cup alpine skiers during the competitive season. Methods: Retrospective interviews were performed with all World Cup athletes from 10 nations at the end of the 2006–7 and 2007–8 winter seasons, and all acute injuries occurring during the 4.5-month competitive season were recorded. If the athlete was not present, their coaches or medical personnel were interviewed. Results: A total of 191 acute injuries were recorded among 521 World Cup alpine skiers. As many as 86 injuries (45%) occurred during World Cup/World Ski Championship competitions, corresponding to an injury rate of 9.8 injuries per 1000 runs (95% CI 7.8 to 11.9). The injury rate was found to increase with increasing speed (slalom 4.9 injuries per 1000 runs, 95% CI 2.5 to 7.4—giant slalom 9.2, 5.1 to 13.3—super-G 11.0, 5.2 to 16.8—downhill 17.2, 11.6 to 22.7). The most frequently injured body part was the knee, with 68 injuries (36%), and 37 of these were severe. The overall injury rate was higher in males than in females, but not for knee injuries. Conclusions : The risk of injury among World Cup athletes in alpine skiing is even higher than previously reported. The knee is the most commonly injured body part and with many severe injuries. Injury rate increased with a higher speed and was higher among males than in females.

Injuries among World Cup ski and snowboard athletes.

There is little information available on injuries to World Cup skiers and snowboarders. The aim of this study was to describe and compare the injury risk to World Cup athletes in alpine skiing, freestyle skiing, snowboarding, ski jumping, Nordic combined and cross country skiing. We performed retrospective interviews with the International Ski Federation (FIS) World Cup athletes from selected nations during the 2006–2007 and 2007–2008 winter seasons and recorded all acute injuries occurring during the seasons. We interviewed 2121 athletes and recorded 705 injuries. There were 520 (72%) time‐loss injuries and 196 (28%) severe injuries (absence >28 days). In freestyle skiing, alpine skiing and snowboarding, there were 27.6, 29.8 and 37.8 time‐loss and 14.4, 11.3 and 13.8 severe injuries per 100 athletes per season, respectively. In Nordic combined, ski jumping and cross country skiing, there were 15.8, 13.6 and 6.3 time‐loss and 3.3, 5.6 and 0.7 severe injuries per 100 athletes per season, respectively. In conclusion about 1/3 of the World Cup alpine, freestyle and snowboard athletes sustain a time‐loss injury each season, while the risk is low in the Nordic disciplines. A particular concern was the high proportion of severe injuries observed among alpine, freestyle and snowboard athletes, which is in contrast to most other sports.

Recording injuries among World Cup skiers and snowboarders: a methodological study

No long‐term injury surveillance programs exist for competitive skiing or snowboarding. The objective of this study was, therefore, to compare different methods to record injuries among World Cup athletes in alpine, freestyle, and cross‐country skiing, snowboarding, ski jumping and Nordic combined. Information regarding injuries sustained during the 2006–2007 winter season was recorded through three separate and independent systems: prospective injury reports by technical delegates (TD) from the International Ski Federation, prospective medical team registration by selected teams, and retrospective athlete interviews at the end of the season. A total of 100 unique injuries to 602 World Cup athletes were identified from any of the three recording methods. Of these, 91% were registered through the athlete interviews, 47% by the medical team registration and 27% by the TD reports. Only 20 injuries (20%) were captured by all three methods. A total of 64 time‐loss injuries were registered. The interviews captured 60 (94%), the medical team registration 39 (61%), and the TD reports 23 (36%) time‐loss injuries, while 18 (28%) were registered by all three systems. Retrospective interviews with athletes/coaches regarding injuries during the last 6 months gave the most complete picture of injuries to World Cup skiers and snowboarders.

Injuries among World Cup freestyle skiers

Background Limited knowledge exists on injuries among professional freestyle skiers. Objective To describe the risk of injury and injury patterns among competitive World Cup (WC) freestyle skiers during the competitive season. Methods Retrospective interviews were conducted with WC freestyle skiers from 20 nations in a cohort study at the end of the 2006–2007, 2007–2008 and 2008–2009 winter seasons, and all acute injuries occurring during the 4.5 month competitive season were recorded. If an athlete was not present, we interviewed his or her coach or medical personnel. Results A total of 291 acute injuries were recorded among 662 WC freestyle skiers. Ninety-three injuries (32%) were severe in nature, defined as >28 days absence from training/competition. This corresponds to 14 (95% CI 11.2 to 16.9) injuries per 100 athletes per season. The most frequently injured body part was the knee with 77 injuries (27%) and 37 of these were severe. The head was the next most commonly injured body part with 39 (13%) injuries. As many as 106 injuries (36%) occurred during WC/World Ski Championship competitions, corresponding to an injury rate of 15.6 injuries per 1000 runs (95% CI 12.7 to 18.6). There were no significant differences between men and women in either the injury rate or the rate seen for knee injuries. Conclusions The injury rate among WC athletes in freestyle skiing is high, especially for severe injuries. The knee is the most commonly injured body part, also dominated by severe injuries. We found no significant difference in the injury rate related to sex.

Injury situations in Freestyle Ski Cross (SX): a video analysis of 33 cases

Background Although injury risk in Freestyle Ski Cross (SX) is high, little is known about the situations leading up to time-loss injuries. Objective To describe the situations leading up to time-loss injuries in elite Freestyle SX. Study design Descriptive video analysis. Methods Thirty-three video recordings of SX injuries reported through the International Ski Federation Injury Surveillance System for four World Cup seasons (2006/2007 through 2010) were obtained. Five experts in the fields of sport medicine and SX analysed each case to describe in detail the situation leading up to the injury (skiing situation and skier behaviour). Results Injuries occurred in four different skiing situations: jumping (n=16), turning (n=8), jumping and turning (n=7) and rollers (n=2). All injured skiers lost control before time of injury (n=33), due to skier–opponent contact (n=13), technical errors (n=8) or inappropriate strategy (n=8), which led to a fall (n=29). Contact occurred in 21 of 33 cases, usually unintentional at landing or take-off, caused by the opponent (n=11) or injured skier (n=8). The technical error cases (n=8) were dominated by bad jumping technique (n=6) and too much inside lean in turning situations (n=2), while inappropriate course line and bad timing at take off (n=7) dominated the inappropriate strategy cases (n=8). Conclusions We identified four main injury situations in elite SX, dominated by jumping situations. The primary cause of injury was unintentional skier–opponent contact in jumping, bank turning and roller situations. Another common cause of injury was personal errors (inappropriate technique and strategy) at take-off and in turning situations.

Time-dependent improvement in functional outcome following Oxford medial unicompartmental knee arthroplasty. A prospective longitudinal multicenter study involving 96 patients.

Background and purpose 10-year survival rates after unicompartmental knee replacement (UKR) have been up to 97% in single-center studies, but they have been as low as 80% in studies from arthroplasty registers. Few studies have evaluated short-term functional outcome and its improvement with time. We determined the time course of functional outcome as evaluated by the knee injury and osteoarthritis outcome score (KOOS) over the first 2 years after Oxford medial UKR. Patients and methods In a prospective multicenter study, we included 99 unselected knees (96 patients, mean age 65 (51–80) years, 57 women) operated with Oxford medial UKR at 3 hospitals in the southeast of Norway between November 2003 and October 2006. Data were collected by independent investigators preoperatively and at 6 weeks, 3 months, 6 months, 1 year, and 2 years postoperatively. KOOS and range of motion (ROM) were determined at all follow-ups. Results Mean KOOS values for pain and activities of daily living were improved already after 6 weeks, and increased between each time point up to 2 years postoperatively. However, no statistically significant improvements were seen after 6 months. Mean active and passive ROM gradually improved up to 2 years after UKR, and were then better than before surgery. Interpretation Most of the expected improvements in pain and function after UKR are achieved within 6 months of surgery. Only minimal improvement can be expected beyond this time.

Time-dependent improvement in functional outcome following LCS rotating platform knee replacement

Background and purpose Long-term follow-up studies after total knee replacement (TKR) using an LCS rotating platform have shown survival rates of up to 97%. Few studies have evaluated short-term functional outcome and its improvement over time. We determined the time course of functional outcome as evaluated by the knee injury and osteoarthritis outcome score (KOOS) over the first 4 years after TKR using the LCS mobile bearing. Patients and methods 50 unselected patients (mean age 70 (40–85) years, 33 women) with osteoarthritis in one knee underwent TKR with an LCS mobile bearing. Data were collected by an independent investigator preoperatively and at 6 weeks, 3 months, 6 months, 1 year, 2 years and 4 years postoperatively. KOOS, a self-assessment function score validated for this purpose, and range of motion (ROM) were determined at all follow-ups. Results The mean KOOS pain score increased from 43 before surgery to 66 at 6 weeks and 88 at 2 years. It was 84 at 4 years. The mean KOOS activities of daily living score (ADL) increased from 49 before surgery to 73 at 6 weeks, then gradually to 90 at 2 years. It decreased to 79 at 4 years. Mean passive ROM was 112° before surgery, 78° at departure from hospital, and then gradually increased to 116° at 2 years and 113° at 4 years. Interpretation Recovery after TKR is time-dependent. Most of the expected improvement in pain and function is achieved at 6 months postoperatively, but some further improvement can be expected up to 2 years postoperatively. ROM will also gradually improve up to 2 years after TKR, and reach the same level as before surgery.

Intraarticular location predicts cartilage filling and subchondral bone changes in a chondral defect.

Background and purpose The natural history of, and predictive factors for outcome of cartilage restoration in chondral defects are poorly understood. We investigated the natural history of cartilage filling subchondral bone changes, comparing defects at two locations in the rabbit knee. Animals and methods In New Zealand rabbits aged 22 weeks, a 4-mm pure chondral defect (ICRS grade 3b) was created in the patella of one knee and in the medial femoral condyle of the other. A stereo microscope was used to optimize the preparation of the defects. The animals were killed 12, 24, and 36 weeks after surgery. Defect filling and the density of subchondral mineralized tissue was estimated using Analysis Pro software on micrographed histological sections. Results The mean filling of the patellar defects was more than twice that of the medial femoral condylar defects at 24 and 36 weeks of follow-up. There was a statistically significant increase in filling from 24 to 36 weeks after surgery at both locations. The density of subchondral mineralized tissue beneath the defects subsided with time in the patellas, in contrast to the density in the medial femoral condyles, which remained unchanged. Interpretation The intraarticular location is a predictive factor for spontaneous filling and subchondral bone changes of chondral defects corresponding to ICRS grade 3b. Disregarding location, the spontaneous filling increased with long-term follow-up. This should be considered when evaluating aspects of cartilage restoration.