Hans H. Paessler

Synovial fluid cytokine concentrations as possible prognostic indicators in the ACL-deficient knee

Approximately 44% of patients develop osteoarthritis (OA) following rupture of the anterior cruciate ligament (ACL) if the injury is left unrepaired. Restoring knee stability through reconstruction, while providing symptomatic relief, has not been shown to reduce the incidence of degenerative changes. In fact, recent studies have shown that 50%–60% of ACL-reconstructed patients go on to develop degenerative changes or frank osteo-arthritis. In light of these data, our group suggests that the cause of post-traumatic osteoarthritis is not biomechanical but biochemical. To test this hypothesis, we measured levels of nine cytokines which are important in modulating physiological and pathophysiological metabolism of cartilage in knee joint synovial fluid following ACL rupture. Our patient population contained both acute und chronic ACL ruptures. A total of 84 samples were collected and analyzed by enzyme-linked immunosorbent assay. On the basis of the data collected, we were able to identify subgroups of patients who, on the basis of their synovial fluid cytokine profile, may be at greater or leasser risk of developing post-traumatic OA. In general, patients displayed concentrations of interleukin-1α (IL-1α), basic fibroblastic growth factor (bFGF), transforming growth factor-β (TGF-β), granulocyte/macrophage-colony stimulating factor (GM-CSF), IL-6, and IL-8 that we interpreted as being consistent with an inflammatory reaction. Of great interest is the fact that the levels of these cytokines were very similar in patients 4 weeks after injury and in chronic patients, leading us to hypothesize that a chronic smoldering inflammatory reaction persists after resolution of the acute effusion. This chronic inflammatory reaction could be the cause of cartilage degeneration seen in patients after ACL reconstruction. Furthermore, this study identified two distinct subpopulations of patients with dramatically differing levels of IL-1β and TNF-α in their synovial fluids. IL-1β and TNF-α were either high acutely and decreased to moderate levels over time, or they were zero acutely and remained zero or low. This is likely to be a very important observation as these two cytokines are key components of the inflammatory response and are the main intra-articular cytokines that provoke cartilage loss. It is our hypothesis that the group with high levels of IL-1β and TNF-α contains the 50%–60% of the patient population which goes on to develop OA, despite knee stabilization with ACL reconstruction. Conversely, we suggest that the group whose synovial fluid contains no IL-1β or TNF-α is protected from developing OA post-traumatically. IL-1-receptor antagonist protein (IRAP), the cytokine that antagonizes the biological effects of IL-1, was present acutely in our patient population; however, it was undetectable in chronic ACL-deficient knees. These data suggest the loss with time of an important cartilage-protective cytokine. The lack of IRAP chronically may allow IL-1β to act in an unrestrained manner resulting in cartilage loss. In addition, IL-1β promotes the secretion of many other inflammatory cytokines which may result in the chronic smoldering inflammatory reaction referred to above. These data encourage further study of the evaluation of cytokine concentrations in the ACL-deficient joint as a means of obtaining both prognostic and mechanistic information of clinical value to the physician.

Anterior Cruciate Ligament Revision Reconstruction Results in 107 Patients

Background Although techniques and options for suitable graft substitutes for anterior cruciate ligament surgery continue to improve, failures occur because of many reasons. Errors in surgical techniques seem to be important reasons. Hypothesis Inappropriate positioning of the tunnels may be the most important reason for these failures. Anatomical anterior cruciate ligament revision reconstruction, using autografts, may yield acceptable outcomes. Study Design Case series; Level of evidence, 4. Methods This retrospective study involved 148 anterior cruciate ligament revision reconstructions performed in our hospital using autografts. One hundred and seven patients were followed up at a mean of 72.9 ± 20.6 months. Clinical evaluation was performed using the Lysholm score, the Tegner rating system, the International Knee Documentation Committee evaluation form, and the KT-1000 arthrometer. Radiographs were evaluated for signs of osteoarthritis according to the Jaeger and Wirth classification. Results Inappropriate positioning of the tunnels was the most important reason (63.5%) for anterior cruciate ligament reconstruction failure. The average Lysholm score improved significantly at the follow-up (88.5±12.4 vs 51.5±24.9; P < .001). Moreover, the average Tegner activity score improved significantly compared with the activity score before revision surgery (6.3±1.8 vs 2.8±1.8; P < .001). The International Knee Documentation Committee score was A in 17 cases, B in 45, C in 37, and D in 8. Radiographic evaluation revealed that 33 patients had degenerative findings of grade I, 35 of grade li, 16 of grade III, and 2 of grade IV. Conclusion Anatomical anterior cruciate ligament revision reconstruction provides satisfactory midterm results as far as stability and function of the knee are concerned. In spite of these favorable subjective and objective results, the radiological evaluation revealed a significant progression of osteoarthritis.

Anterior cruciate ligament reconstruction using patellar tendon versus hamstring tendon: a prospective comparative study with 9-year follow-up.

PURPOSE To analyze the long-term evaluation of clinical, functional, and magnetic resonance imaging (MRI) results after implant-free press-fit anterior cruciate ligament (ACL) reconstruction with bone-patella tendon (BPT) versus quadrupled hamstring tendon (HT) grafts. METHODS Sixty-two ACL-insufficient patients were included in a prospective, randomized study (31 BPT and 31 HT). Both surgical procedures were performed without any implants by a press-fit technique by the senior author. The femoral tunnel was drilled through the anteromedial portal for anatomic placement. At 8.8 years after reconstruction, 53 patients (28 BPT and 25 HT) were examined by different clinical and functional tests. Bilateral MRI scans were performed and interpreted by an independent radiologist. RESULTS On follow-up, the score on the International Knee Documentation Committee evaluation form was significantly better in the HT group. The clinical examination including range of motion, KT-1000 test (MEDmetric, San Diego, CA), and pivot-shift test showed no significant differences. On isokinetic testing, the mean quadriceps strength was close to normal (96%) in both groups, but the hamstring strength was lower in the HT group (100.3%/95.1%). Kneeling (1.5/1.1, P = .002), knee walking (1.72/1.14, P = .002), and single-leg hop test (95.8%/99.1%, P = .057) were better in the HT group. The MRI findings about the mean degree of cartilage lesion (International Cartilage Repair Society protocol) of the operated (2.1/2.1) and nonoperated (1.4/1.8) knee showed no significant differences. No significant difference was found in the grade of medial or lateral meniscal lesion or the number of patients having meniscal lesions when the operated and nonoperated knees were compared. Tunnel measurements, Caton-Deschamps Index, and the sagittal ACL angle were similar. CONCLUSIONS The implant-free press-fit technique for anterior cruciate ligament reconstruction by use of bone-patellar tendon and hamstring grafts with anatomic graft placement is an innovative technique to preserve the cartilage and meniscal status without significant differences between the operated and nonoperated knees in the long term. Significantly less anterior knee pain was noted in the hamstring group, when testing for kneeling and knee walking. LEVEL OF EVIDENCE Level II, prospective comparative study.

Donor Site Morbidity and Return to the Preinjury Activity Level After Anterior Cruciate Ligament Reconstruction Using Ipsilateral and Contralateral Patellar Tendon Autograft A Retrospective, Nonrandomized Study

Aim To compare the donor site morbidity after anterior cruciate ligament reconstruction using ipsilateral and contralateral bone–patellar tendon autograft. Study Design Cohort study; Level of evidence, 2 Patients and Method Between 1997 and 1999, 100 patients underwent anterior cruciate ligament reconstruction with autologous bone–patellar tendon graft. The reconstructions were performed using ipsilateral bone–patellar tendon graft in 52 patients (group Ip) and contralateral bone–patellar tendon graft in 48 patients (group Co). Group Co consisted of 2 subgroups: group Co-D consisted of the donor knees (n = 48) and group Co-ACL consisted of the anterior cruciate ligament–reconstructed knees (n = 48). Mean follow-up was 39.2 months. Donor site morbidity was evaluated with a questionnaire, computerized historical data, KT-2000 arthrometer measurements, the Cincinnati score, and the Tegner score. Results KT-2000 arthrometer evaluation showed a mean side-to-side difference of 0.6 mm in both groups. There were no significant differences between the 2 groups concerning the Cincinnati and Tegner scores. With regard to local tenderness, a significantly higher rate was found in group Ip (59.6%) and group Co-D (58.3%) compared with group Co-ACL (6.3%). In groups Ip and Co-D, high statistically significant differences were also found according to kneeling pain (69.2% and 70.8%, respectively) and knee-walking pain (76.9% and 70.8%, respectively) compared with group Co-ACL (6.3% and 10.4%, respectively). With regard to numbness, there was no statistical significance between the rates of all 3 groups: group Ip = 75%, group Co-D = 85.4%, and group Co-ACL = 64.6%. There was one rupture of the patellar tendon and one patient with chronic patellar tendinitis, both in the donor knee of group Co-D. Conclusion The contralateral bone–patellar tendon graft appears to present no advantage over the ipsilateral graft, as all symptoms concerning donor site morbidity are shifted from the injured into the healthy knee, and return to activity is not more rapid.

Arthroscopic Resection of the Lower Patellar Pole in Patients With Chronic Patellar Tendinosis

PURPOSE The aim of this prospective study is to evaluate the clinical results of arthroscopic resection of the lower patellar pole in patients with patellar tendinosis. METHODS Twenty patients underwent an arthroscopic resection of the lower patellar pole between 2002 and 2004. All of them were evaluated at 6 weeks and 3, 6, 12, and 24 months after surgery using the Tegner activity level, the Lysholm score, the Kujala score, a modified jumpers knee classification according to Blazina, and visual analog scales for pain, function, and satisfaction. Clinical evaluation was performed 2 years after surgery. In addition, magnetic resonance imaging was performed preoperatively and at a 2-year follow-up. RESULTS By 6 weeks postoperatively and at every other follow-up visit, significant improvements were seen in the Lysholm score (P = .001), the Kujala score (P = .001) and the visual analog scales. The Tegner score improved significantly by 3 months postsurgery (P = .01). Two years after surgery, the Tegner score improved from 4.4 +/- 2.9 to 7.95 +/- 1.6 (P < .0001); the Lysholm score from 57.1 +/- 17.1 to 97.3 +/- 4.4 (P < .0001); and Kujala score from 53.7 +/- 14.7 to 95.4 +/- 7.8 (P < .0001). The jumpers knee classification showed excellent (stage 0) or good (stage I) results in 18 of 20 patients. At follow-up, all but one magnetic resonance image showed hypodens areals in the proximal aspect of the patellar tendon, and small osteophytes were seen in some cases at the resection area. These findings did not seem to have any influence on the results. CONCLUSIONS The arthroscopic resection of the lower patellar pole as a minimal invasive method to treat jumpers knee provides satisfactory clinical results in knee function and pain reduction with fast recovery and return to sport activities. LEVEL OF EVIDENCE Level IV, therapeutic case series.

The Effectiveness of Supplementing a Standard Rehabilitation Program With Superimposed Neuromuscular Electrical Stimulation After Anterior Cruciate Ligament Reconstruction A Prospective, Randomized, Single-Blind Study

Background: Rehabilitation after anterior cruciate ligament reconstruction is a key determinant affecting patient return to usual activity levels. Neuromuscular electrical stimulation is a treatment that can counteract strength loss and serve as an adjunct to conventional therapy. Purpose: To compare the effect of adding traditional neuromuscular electrical stimulation (Polystim) or a novel garment-integrated neuromuscular electrical stimulation (Kneehab) to a standard postoperative rehabilitation program (control). Study Design: Randomized controlled trial; Level of evidence, 1. Methods: Ninety-six patients, of a total enrolled cohort of 131 patients randomized to 1 of 3 intervention groups, completed a standard rehabilitation program. In addition, the 2 neuromuscular electrical stimulation groups underwent 20-minute sessions of neuromuscular electrical stimulation 3 times a day, 5 days a week, for 12 weeks, in which stimulation was superimposed on isometric volitional contractions. Outcome measures including isokinetic strength of the knee extensors of the injured and uninjured leg at 90 and 180 deg/s, along with functional tests of proprioception, were assessed at baseline and at 6 weeks, 12 weeks, and 6 months postoperatively. Results: The Kneehab group achieved significantly better results at each time point compared with the Polystim and control groups (P < .001). Extensor strength of the Kneehab group at speeds of 90 and 180 deg/s increased by 30.2% and 27.8%, respectively, between the preoperative measurements and the 6-month follow-up point in the injured leg. The corresponding changes for Polystim were 5.1% and 5%, whereas for the control group they were 6.6% and 6.7%, respectively. The mean single-legged hop test hop score of the Kneehab group improved by 50% between the 6-week and 6-month follow-up, whereas the corresponding changes for the Polystim and control groups were 26.3% and 26.2%, respectively. Although there was no significant difference between the groups with respect to the Tegner score and the International Knee Documentation Committee 2000 knee examination score, the Kneehab group showed a significant difference in mean improvement for the baseline corrected Lysholm score compared with the control group (P = .01; 95% confidence interval, 1.12-8.59) and with the Polystim group (P < .001; 95% confidence interval, 1.34-9.09) with no significant difference evident between Polystim and control groups (P = .97; 95% confidence interval, −4.23 to 3.51). Conclusion: Intensive garment-integrated stimulation combined with standard rehabilitation is effective at accelerating recovery after knee surgery.

How new is the Lachman test

more common during the last decade. This situation is partly because of the rising rate of ACL injury as the result of increased athletic activity, and partly because of the improved diagnosis of ACL injuries. Among the noninvasive clinical diagnostic tests available to us, the Lachman test has proven to be the most reliable. Who, one may wonder, is Lachman? John W. Lachman, MD (Fig. 1), was Chairman and Professor of Orthopaedic Surgery at Temple University in Philadelphia, Pennsylvania, from 1956 to 1989 (Lachman J, personal communication). He had observed early on that some patients with ACL tears have a passive anterior subluxation of the tibia in relation to the femur when they are in the supine position. Eventually, he found that ACL instability could be demonstrated quite easily by applying stress to the extended knee joint and that this method was more effective than using the conventional anterior drawer test. 11 Joseph S. Torg, MD, finished his surgical training in Dr. Lachman’s department in 1968 and stayed on at Temple University. He first reported on &dquo;The Lachman Test,&dquo; which he named in honor of his mentor, at the annual meeting of the American Orthopaedic Society for Sports Medicine in 1976 in New Orleans. Subsequently, Dr. Torg and colleagues published a paper in The American Journal of Sports Medicine12 documenting the validity of the Lachman test. Dr. Lachman himself has never claimed to be the originator of this widely used test. A review of the world literature reveals some interesting facts. In 1960, an American, Colonel S. J. Ritchey, had described this same ACL test in considerable detail: &dquo;...To test the anterior cruciate, the knee is extended in a comfortable position. The index finger is placed in the small triangle formed by the curved femoral condyle and straight tibial plateau medially. The palm of this same hand stabilizes the femur while the second hand

Augmented repair and early mobilization of acute anterior cruciate ligament injuries

This paper describes a technique for repair of the anterior cruciate ligament with protection of that repair by a synthetic augmentation device. Of 61 patients who underwent surgery 24 to 57 months (mean, 38.3) be fore data accumulation, 57 returned for followup. Sub jectively, 53 (93%) patients reported a good or excellent functional result; however, only 29 (51 %) of the patients returned to their preinjury sports level. Objectively, a radiographic Lachman test was performed on both the injured and the noninjured knee of all 57 patients. The preoperative mean difference between the knees was 8.6 mm (range, 4.6 to 17.2) and at followup it was 2.4 mm (range, -0.9 to 11.8). Radiographic abduction and adduction stress tests demonstrated stable healing of the (unrepaired) collateral ligament lesions (varus stress = 0.1 mm and valgus stress = 0.4 mm mean side-to- side difference), indicating that suturing of ruptured collateral ligaments is not necessary when the knee is centrally stabilized with the augmentation device. These results indicate that successful repair of the anterior cruciate ligament is frequently possible when enhanced with an augmentation device.

Intra-articular temperatures of the knee in sports - an in-vivo study of jogging and alpine skiing.

BackgroundUp to date, no information exists about the intra-articular temperature changes of the knee related to activity and ambient temperature.MethodsIn 6 healthy males, a probe for intra-articular measurement was inserted into the notch of the right knee. Each subject was jogging on a treadmill in a closed room at 19°C room temperature and skiing in a ski resort at -3°C outside temperature for 60 minutes. In both conditions, temperatures were measured every fifteen minutes intra-articulary and at the skin surface of the knee. A possible influence on joint function and laxity was evaluated before and after activity. Statistical analysis of intra-articular and skin temperatures was done using nonparametric Wilcoxons sign rank sum test and Mann-Whitneys-U-Test.ResultsMedian intra-articular temperatures increased from 31.4°C before activity by 2.1°C, 4°C, 5.8°C and 6.1°C after 15, 30, 45 and 60 min of jogging (all p ≤ 0.05). Median intra-articular temperatures dropped from 32.2°C before activity by 0.5°C, 1.9°C, 3.6°C and 1.1°C after 15, 30, 45 and 60 min of skiing (all n.s.). After 60 minutes of skiing (jogging), the median intra-articular temperature was 19.6% (8.7%) higher than the skin surface temperature at the knee. Joint function and laxity appeared not to be different before and after activity within both groups.ConclusionThis study demonstrates different changes of intra-articular and skin temperatures during sports in jogging and alpine skiing and suggests that changes are related to activity and ambient temperature.

The Effectiveness of Reconstruction of the Anterior Cruciate Ligament Using the Novel Knot/Press-Fit Technique A Cadaveric Study

Background A variety of fixation devices are used for anterior cruciate ligament reconstruction with hamstring tendon grafts. These devices increase costs and can present artifacts in magnetic resonance imaging as well as complications in revision surgery. Therefore, a novel knot/press-fit technique that requires no implantable devices has been introduced. Null Hypothesis The knot/press-fit technique restores knee kinematics as well as the more commonly used EndoButton CL fixation and has similar biomechanical properties as other devices published in the literature. Study Design Controlled laboratory study. Methods Eight fresh-frozen cadaveric knees (52 ± 7 years) were tested using a robotic/universal force-moment sensor testing system. The knee kinematics of the intact, anterior cruciate ligament-deficient, EndoButton-reconstructed, and knot/pressfit-reconstructed knee in response to both a 134-N anterior tibial load and a combined rotatory load at multiple knee flexion angles was determined. Differences between the 4 knee states were evaluated with a 2-factor repeated-measures analysis of variance (P <. 05). To determine the stiffness and strength of the knot/press-fit fixation, the femur-graft-tibia complex was tested in uniaxial tension. Results In response to an anterior tibial load, the anterior tibial translation for the knot/press-fit reconstruction was found to be not significantly different from that of the intact anterior cruciate ligament as well as that of the EndoButton reconstruction (P >. 05). In response to a combined rotatory load, neither reconstruction procedure could effectively reduce the coupled anterior tibial translation to that of the intact knee, and no significant difference between the 2 reconstructions could be detected (P >. 05). The stiffness of the knot/press-fit complex was found to be 37.8 ± 9.6 N/mm, and the load at failure was 540 ± 97.7 N, which is equal to other devices published in the literature. Clinical Relevance The experiment suggests that the knot/press-fit technique may be a reliable alternative for the femoral fixation of hamstring tendon grafts.