Implant-free ACL reconstruction: a review.

Implant-free anterior cruciate ligament (ACL) reconstruction is the fixation of ACL grafts without the need for artificial implants. Our aim was to study the evolution of this technique, review the biomechanical evidence and summarise the results. Implant-free graft fixation for bone patella tendon ACL reconstruction was first described in 1987. This concept of implant-free graft fixation was adapted for hamstring and quadriceps tendons as alternative graft sources. Various biomechanical studies have reported that by adhering to certain technical details, this technique provides comparable fixation strength as conventional ACL fixation. The outcome studies of implant-free ACL reconstruction also report clinical results similar to ACL reconstruction with conventional implants.

Emerging techniques in orthopedics: advances in neuromuscular electrical stimulation.

Neuromuscular electrical stimulation (NMES) is defined as the application of an electric current to neuromuscular tissue to elicit a muscle contraction. It is typically applied in a clinical setting to strengthen muscle, particularly the quadriceps femoris, through repetitive contractions. Most studies to date involving NMES have been conducted using conventional lead-wired, or "single path" devices, and while effective, these devices have inherent limitations around comfort and incomplete muscle recruitment. In a prospective, randomized, controlled, single-blind trial, investigators found that using a novel "Multipath" device was effective when combined with standard rehabilitation in accelerating recovery after anterior cruciate ligament reconstruction. Additional research is warranted to explore whether this effect also occurs after other types of knee surgery.

Prone position for minimal invasive or all-arthroscopic autologous chondrocyte implantation at the patella.

Full size retropatellar cartilage lesions are troublesome conditions to treat and an autologous chondrocyte implantation with or without matrix or scaffold in supine position is difficult. Usually, it is necessary to perform a large arthrotomy to evert the patella in order to get sufficient access to the retropatellar cartilage defect. The procedure is associated with a significant parapatellar soft tissue trauma to the patient. This technical note introcudes a minimal invasive approach with the patient in prone position using an all-arthroscopic or mini-open technique to treat retropatellar full size articular cartilage lesions of the patella.

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.

Intra-operative hamstring tendon graft contamination in anterior cruciate ligament reconstruction.

We aimed to evaluate the possibility of hamstring tendon contamination, the correlation with clinical infection and its association with C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) values in 89 anterior cruciate ligament reconstructions. Two tissue samples were obtained for culture from each graft: immediately after harvesting the graft and before implantation. The ESR and the CRP were evaluated preoperatively and on the 4th and 20th postoperative days. Nine patients (10%) had positive cultures but no patient had signs of postoperative infection. All patients had ESR and CRP values elevated at the 4th postoperative day. ESR and CRP values returned to normal levels at the 20th postoperative day. Higher mean values of CRP levels at the 4th day were observed in patients with contaminated grafts compared to those with uncontaminated. Both values reached normal levels at the 20th postoperative day.

Allergic reaction to biodegradable interference poly-L-lactic acid screws after anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft.

We report a case of a systemic allergic reaction to biodegradable poly-L-lactic acid (PLLA) interference screws after anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone graft. A 30-year-old patient complained of certain symptoms, such as an inability to focus mentally, rash on the right femur, chronic fatigue, decreased sex drive, and localized alopecia, 3 months after ACL reconstruction in the right knee. Two biodegradable PLLA interference screws had been used for proximal and distal graft fixation. Allergy testing showed a value of 7 in PLLA antigen. After removal of 1 screw in August 2000, the patient reported marked improvement, but some symptoms remained. In July 2001 he underwent arthroscopic revision ACL reconstruction with hamstrings via an implant-free technique with intensive debridement of the tunnels and removal of all scar tissue and screw rests. All symptoms disappeared, and the PLLA antigen number fell from 3 to "concentrate" 2 months postoperatively.

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

BACKGROUND: Up to date, no information exists about the intra-articular temperature changes of the knee related to activity and ambient temperature. METHODS: In 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 degrees C room temperature and skiing in a ski resort at -3 degrees 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 Wilcoxon's sign rank sum test and Mann-Whitney's-U-Test. RESULTS: Median intra-articular temperatures increased from 31.4 degrees C before activity by 2.1 degrees C, 4 degrees C, 5.8 degrees C and 6.1 degrees C after 15, 30, 45 and 60 min of jogging (all p < or = 0.05). Median intra-articular temperatures dropped from 32.2 degrees C before activity by 0.5 degrees C, 1.9 degrees C, 3.6 degrees C and 1.1 degrees 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. CONCLUSION: This 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.

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 II, 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.

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 jumper's 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 jumper's 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 jumper's 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 influence of the lower patellar pole in the pathogenesis of chronic patellar tendinopathy.

Resection of the lower patellar pole provides good results in the treatment of jumper's knee. Therefore we hypothesized that the length of the lower patellar pole is increased in patients with chronic patellar tendinopathy. Cohort study, level of evidence 2. Between 2000 and 2005, 25 patients with chronic patellar tendinopathy underwent conservative and surgical treatment in our clinic. All of them had preoperative MRI were three independent examiners measured the Caton Index, the length and the ratio of the articular and non-articular patellar surface, tendon length and thickness and the thickness and length of the hypodens lesions in the patellar tendon. The measurements were compared with 50 MRI of a control group with no clinical patellofemoral disorders or patellar tendinopathy. Significant changes in tendon thickness (9.42+/-2.87 vs. 4.88+/-1.13; P<0.0001), a longer non-articular surface of the patella (10.62+/-2.86 vs. 7.098+/-2.53; P<0.0001) and significant higher ratio between the articular and the non-articular patellar surface (0.32 vs. 0.24; P<0.0001) were found in the jumper's knee group. No significant changes were seen in the length of the articular surface or the Caton Index. The development of chronic patellar tendinopathy in athletes might be associated with a longer lower patellar pole as patients with jumper's knee showed a longer non-articular patellar surface compared with the control group.

Effects of a contoured articular prosthetic device on tibiofemoral peak contact pressure: a biomechanical study.

Many middle-aged patients are affected by localized cartilage defects that are neither appropriate for primary, nor repeat biological repair methods, nor for conventional arthroplasty. This in vitro study aims to determine the peak contact pressure in the tibiofemoral joint with a partial femoral resurfacing device (HemiCAP, Arthrosurface Inc., Franklin, MA, USA). Peak contact pressure was determined in eight fresh-frozen cadaveric specimens using a Tekscan sensor placed in the medial compartment above the menisci. A closed loop robotic knee simulator was used to test each knee in static stance positions (5 degrees /15 degrees /30 degrees /45 degrees ) with body weight ground reaction force (GRF), 30 degrees flexion with twice the body weight (2tBW) GRF and dynamic knee-bending cycles with body weight GRF. The ground reaction force was adjusted to the living body weight of the cadaver donor and maintained throughout all cycles. Each specimen was tested under four different conditions: Untreated, flush HemiCAP implantation, 1-mm proud implantation and 20-mm defect. A paired sampled t test to compare means (significance, P < or = 0.05) was used for statistical analysis. On average, no statistically significant differences were found in any testing condition comparing the normal knee with flush device implantation. With the 1-mm proud implant, statistically significant increase of peak contact pressures of 217% (5 degrees stance), 99% (dynamic knee bending) and 90% (30 degrees stance with 2tBW) compared to the untreated condition was seen. No significant increase of peak contact pressure was evaluated with the 20-mm defect. The data suggests that resurfacing with the HemiCAP does not lead to increased peak contact pressure with flush implantation. However, elevated implantation results in increased peak contact pressure and might be biomechanically disadvantageous in an in vivo application.

Changes of the posterior meniscal horn height during loading: an in vivo magnetic resonance imaging study.

This in vivo magnetic resonance imaging study evaluated the deformation of the meniscal posterior horn during loading. Images of the medial and lateral meniscus were obtained in 20 normal knees in 0 degrees and 30 degrees of flexion, and the height of the posterior horn of both menisci was measured. Mean height of the posterior horn of the medial meniscus under no load and load equal to 50% and 100% body weight was 6.8, 6.3, and 6 mm, respectively (P<.05). Mean height of the posterior horn of the lateral meniscus under no load and load equal to 50% and 100% body weight was 7.6, 7.2, and 6.9 mm, respectively (P<.05). Knee position (0 degree versus 30 degrees of flexion) at a constant load resulted in no significant change in height. These results show height of the posterior horn of the medial and lateral meniscus decrease with increasing loading and angle of knee flexion.

Comparative analysis of the morphologic structure of quadriceps and patellar tendon: a descriptive laboratory study.

PURPOSE: The difference in ultimate strength between the quadriceps and patellar tendon could be reflected by different morphologic features. METHODS: Standardized samples of quadriceps and patellar tendons were harvested from 20 cadavers and were investigated via light and electron microscopy, immunohistochemistry, and morphometry. The thickness of collagen fibrils, fibril-interstitium ratio, density of blood vessels, density of fibroblasts, and distribution of collagen fibrils were analyzed. RESULTS: In comparison with the patellar tendon, the quadriceps tendon showed a significantly higher fibril-interstitium ratio (P = .0004) and a higher fibroblast density (P = .0011). No differences regarding the thickness of collagen fibrils, density of blood vessels, and distribution of fibrils were found. CONCLUSIONS: The quadriceps tendon graft can provide approximately 20% more collagen than the patellar tendon graft with the same thickness. This fact can play an important role in the better ultimate strength of the quadriceps tendon. CLINICAL RELEVANCE: The detailed anatomic description of the quadriceps tendon and patellar tendon explains the difference in their ultimate strength.

Morphologic and histologic comparison between the patella and hamstring tendons grafts: a descriptive and anatomic study.

PURPOSE: Morphologic and histologic comparison of patella and hamstring tendon grafts. METHODS: Hamstring tendons (semitendinosus and gracilis) and patellar tendons were taken from 20 cadaveric knees and were investigated by using light and electron microscopy, immunohistochemistry, and morphometry. The thickness of collagen fibrils, fibril/interstitum ratio, density of blood vessels, density of fibroblasts, and distribution of the collagen fibrils were analyzed. RESULTS: The semitendinosus and gracilis tendons provide 20% and 30% more fibril/interstitum ratio compared with the patella tendon (P = .0056 and .0028). Also, the density of fibroblasts was 50% and 35% more (P = .0061 and .0050). No differences regarding the thickness of the collagen fibrils, density of blood vessels, and distribution of the fibrils were found. CONCLUSIONS: Both semitendinous and gracilis tendons provide significantly more density of collagen fibrils as well as density of fibroblasts in comparison with patellar tendons. These findings provide a potential advantage of the hamstrings group on better remodelling and regeneration of the tissue. CLINICAL RELEVANCE: These grafts have been used as autografts for anterior cruciate ligament reconstruction. Despite the interest on these tendons, their microscopic structure has not been sufficiently investigated yet.

Results of all-inside meniscal repair with the FasT-Fix meniscal repair system.

PURPOSE: The goal of this prospective study was to evaluate the results of arthroscopic meniscal repair using the FasT-Fix repair system. TYPE OF STUDY: Prospective case series. METHODS: Sixty-one meniscal repairs with the FasT-Fix meniscal repair system in 58 patients with a mean age of 32.6 years were performed between 2001 and 2002. Concurrent anterior cruciate ligament reconstruction was performed in 36 patients (62%). All tears were longitudinal and located in the red/red or red/white zone. Criteria for clinical success included absence of joint-line tenderness, locking, swelling, and a negative McMurray test. Clinical evaluation also included the Tegner and Lysholm knee scores, and KT-1000 arthrometry. In addition, all patients were evaluated preoperatively with magnetic resonance imaging. RESULTS: The average follow-up was 18 months (range, 14 to 28 months). Six of 61 repaired menisci (9.8%) were considered failures according to our criteria. Therefore, the success rate was 90.2%. Time required for meniscal repair averaged 11 minutes. Postoperatively, the majority of the patients had no restrictions in sports activities. The mean Lysholm significantly improved from 43.6 preoperatively to 87.5 postoperatively (P < .001). Fifty-one patients (88%) had an excellent or good result according to the Lysholm knee score. Four patients had a restriction of knee joint motion postoperatively, and an arthroscopic arthrolysis was performed in 1 of them. Analysis showed that age, length of tear, simultaneous anterior cruciate ligament reconstruction, chronicity of injury, and location of tear did not affect the clinical outcome. CONCLUSIONS: Our results show that arthroscopic meniscal repair with the FasT-Fix repair system provided a high rate of meniscus healing and appeared to be safe and effective in this group of patients. LEVEL OF EVIDENCE: Level IV, therapeutic study, case series (no control group).

Changes of meniscal interhorn distances: an in vivo magnetic resonance imaging study.

The aim of this study was to evaluate the changes of the internal (IID) and external meniscal interhorn distance (EID) of the medial and the lateral meniscus under loading. Sagittal magnetic resonance images of 15 knees were studied. The medial and lateral meniscus were examined with the knee at 0 degrees and 30 degrees of flexion, under no load, with load equal to 50% of body weight and with load equal to 100% of body weight. Under no load, the mean IID was 19.9 mm for the medial meniscus and 12.3 mm for the lateral meniscus and the mean EID was 44.6 mm for the medial meniscus and 34.4 mm for the lateral meniscus. Under load equal to 50% and 100% of patient's body weight, there was a significant increase in both distances (p<0.05). Under constant loading, flexion of the knee from 0 degrees to 30 degrees , decreased the EID of both menisci. In conclusion, loading increases both IID and EID. Knee position affects only the EID. The quality of magnetic resonance images may affect the reliability of such measurements.

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/press-fit-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.

Relationship between tunnel widening and different rehabilitation procedures after anterior cruciate ligament reconstruction with quadrupled hamstring tendons.

BACKGROUND: It has been demonstrated that bone tunnel widening could appear after knee anterior cruciate ligament (ACL) reconstruction, especially for those patients whose ruptured ACL were reconstructed with semitendinosus and gracilis tendons. Many factors can influence the extent of tunnel widening. Few studies have investigated the relationship between bone tunnel widening and rehabilitation procedures. This research was carried out to find the rehabilitation procedures' influence on the tibial bone tunnel widening after ACL reconstruction. METHODS: Sixty-five cases, whose ACL reconstructions were done using quadrupled semitendinosus and gracilis tendons, were divided into two groups. Group A had 33 cases, 19 men, 14 women, averaged (31.2 +/- 12.4) years old, only ACL reconstruction was done using Paessler's technique, and aggressive rehabilitation procedure was used for function recovery post operation. Group B had 32 cases, 20 men, 12 women, averaged (30.3 +/- 10.3) years old. Except for ACL reconstruction, every patient in group B accepted meniscus repair using re-fixation methods or cartilage repair using microfracture technique, conservative rehabilitation procedure was used post operation. Six months post operation, standard posterior-anterior radiographic plates were taken for each case, CorelDRAW 8.0 software was used to digitize all X-ray plates and measure the upper, middle and lower parts of the tibial tunnel. Magnification effect of X-ray plates was taken out after measurement. RESULTS: Six months after ACL reconstruction the tibial tunnel widening of the upper, middle and lower parts on both the posterior-anterior and lateral X-ray plates in Group A with aggressive rehabilitation procedure was much more serious than in Group B with conservative rehabilitation. KT-1000 knee stability measurement and clinical manifestation showed no difference between the two groups. CONCLUSIONS: Rehabilitation procedure after ACL reconstruction is one of the reasons for tunnel widening. It not only can directly influence the function recovery of ACL reconstructed knee, but also perhaps indirectly influence the function recovery and long-term clinical result of the operated knee by influencing the tunnel widening.

Arthroscopic meniscal repair with an absorbable screw: results and surgical technique.

The results of a new method for arthroscopic all-inside meniscus repair using a biodegradable cannulated screw (Clearfix meniscal screw) were assessed in a medium-term follow-up prospective study. The Clearfix meniscal screw system consists of delivery cannulae, screw driver, and screw implants. After tear debridement, a screw is located on the driver and passed through the cannula to the insertion site, holding the two sides of the tear together under linear compression. Forty-eight patients (48 repairs) with a mean age of 32.7 years were included in the study. Ligament stabilizing procedures were done in 39 patients (81%) who had anterior cruciate ligament deficient knees. Only longitudinal lesions in the red/red or red/white zone were repaired. Follow-up averaged 19 months, with a range from 12 to 48 months. Patients were evaluated using clinical examination, the "Orthopaedische Arbeitsgemeinschaft Knie (OAK)" knee evaluation scheme and magnetic resonance imaging (MRI). Criteria for clinical success included absence of joint-line tenderness, absence of swelling and a negative McMurray test. Postoperatively, there were no complications directly associated with the device. Twelve of 48 repaired menisci (25%) were considered failures according to the above-mentioned criteria. According to the OAK knee evaluation scheme, 38 patients (79%) had an excellent or good result. MRI, however, showed persisting grade III or IV lesions in 35 patients (73%). Analysis showed that age, length of tear, and simultaneous anterior cruciate ligament reconstruction did not affect the clinical outcome. In contrast, risk factors for failure of meniscus repair are chronicity of injury, location of tear more than 3 mm from the meniscosynovial junction and meniscus side (medial).