Evaluation of transtibial aiming of the femoral tunnel at its anatomical position in arthroscopical ACL reconstruction.

43 ACL reconstructions with hamstrings’ graft were studied. First, the femoral tunnel was drilled through the anteromedial portal at 09.30–10.00 (14.00–14.30 resp.) and then the tibial tunnel (av. anteroposterior angle: 63,5°, sagittal: 64,2°) at the same diameter with simoultaneous radiological documentation. Then, with a femoral aiming device, we tried to put a K-wire at the center of the drilled femoral tunnel. Fotographic documentation took place. In 20 cases the diameter of the tunnels was 7mm, in 11, 7,5mm, in 7, 8mm, in 3, 8,5mm and in 1, 9mm. Evaluation of all radiological and photographic material from 2 observers followed, according to the deviation of the transtibial K-wire from the center of the femoral tunnel.

38 ACL reconstructions were evaluated. It was shown that in 11 cases the transtibial K-wire was in the femoral tunnel (28,9%) (in 7 with a diameter of 7mm., in 2 with 7,5mm. and in 2 with 8mm.). The K-wire was in 23 cases (60,5%) at the perimeter or out of the femoral tunnel (in 11, with a diameter of 7mm., in 8 with 7,5mm., in 4 with 8mm., in 3 with 8,5mm. and in 1 with 9mm.). There was no correlation with the angles of the tibial tunnel or the age of the patients.

Transtibial aiming of the femoral tunnel at its anatomical position is very difficult and there is no correlation of the transtibial deviation with the diameter of the tibial tunnel.

The goal of this prospective study was to evaluate the results of arthroscopic meniscal repair with the FasT-Fix repair system. Type of study: Prospective case series. Methods: 83 meniscal repairs with the FasT-Fix meniscal repair system in 80 patients with a mean age of 29 years were performed between 2004 and 2008. Concurrent anterior cruciate ligament (ACL) reconstruction was performed in 70% of the cases. 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 included also the Lyscholm knee score, and KT-1000 arthrometry. Results: The average follow-up was 38 months (range, 10–61 months). Six of 83 repaired menisci (7.23%) were considered failures according to our criteria. Therefore, the success rate was 92.77%. Time required for meniscal repair averaged 15 minutes. Postoperatively, the majority of the patients had no restrictions in sports activities. 92% 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 one of them. Analysis showed that, age, length of tear, simultaneous ACL reconstruction, chronicity of injury, and location of tear did not affect the clinical outcome. Conclusions: Our results, shows that arthroscopic meniscal repair with the FasT-Fix repair system provides a high rate of meniscus healing and offers reduction of both the risk of serious neurovascular complications and operative time.

Measurement of precision in positioning multiple autologous osteochondral transplantation in comparison to the conventional free hand technique.

The articular surfaces of 6 cadaveric condyles (medial – lateral) were used. The knee was referenced by a navigation system (Praxim). The pins carrying the navigation detectors were positioned to the femur and to the tibia. The grafts were taken from the donor side (measurement I) with the special instrument which carried the navigation detectors. The recipient site was prepared and the donor osteochondral grafts were forwarded to the articular surface (II). The same procedure took place without navigation. The articular surface congruity was measured with the probe (measurement III)

The angle of the recipient plug removal (measurement I) with the navigation technique was 3,27° (SD 2,05°; 0°–9°). The conventional technique showed 10,73° (SD 4,96°; 2°–17°). For the recipient plug placement (measurement II) under navigated control a mean angle of 3,6° (SD 1,96°; 1°–9°) was shown, the conventional technique showed results with a mean angle of 10,6° (SD 4,41°; 3°–17°). The mean depth (measurements III) under navigated control was 0,25mm (SD 0,19mm; 0mm–0,6mm). With conventional technique the mean depth was 0,55mm (SD 0,28mm; 0,2mm –1,1mm).

The application of navigation showed that complications like diverging of the grafts leading to breakage or loosening as well as depth mismatch which can lead to grafts sitting over or under the articular surface can be avoided providing better results in comparison to the free hand procedure

Background: Navigation allows for determination of the mechanical axis of the lower extremity. We evaluated the intra- and inter-observer reliability with an image-free navigation system and determined the accuracy of the navigation system to monitor changes in lower limb alignment as compared to alignment measured with a novel 3D CT method.

Methods: A total of 13 cadaver legs were used to evaluate the intra- and inter-observer registration reliability by three observers. Navigated HTOs were then performed on all legs and pre/postoperative values of the varus-valgus angles were recorded. Data were compared to equivalent measures obtained by 3D CT using intra-class correlation coefficients (ICCs).

Results: The ICCs for intra-observer varus-valgus reliability ranged from 0.756 to 0.922, inter-observer reliability was 0.644. ICCs for navigation-CT comparison were 0.784 for varus-valgus angle (pre-op), 0.846 (postop) and 0.873 (delta). Maximum differences in navigation-CT measurements in varus-valgus angle (delta) were 4.5° for all trials. There was poor reliability and accuracy in the axial plane (tibial rotation) as well as fair reliability and accuracy in the sagittal plane (tibial slope).

Conclusion: Image-free navigation is reliable for dynamic monitoring of coronal leg alignment but shows relevant limitations in determination of sagittal and axial plane alignment.

Background: A navigated 8 in 1 femoral cutting guide for TKA that does not require primary fixation or intramedullary guides was developed. The hypothesis of our study were twofold: 1) the navigation system allows for precise alignment and adjustment of a new femoral 8 in 1 cutting guide with negligible variance in the initially planned vs. achieved implant position; 2) resulting femoral cuts are very accurate without relevant cutting errors.

Material and Methods: We demonstrate our approach with the Universal Knee Instrument (UKI, Precimed Inc. USA), a versatile 8 in 1 TKA guide designed to perform all femoral cuts with a single jig. We integrated an array of “adjustable constraints” into the UKI by machining four threaded holes directly through the template. Adaptation to a navigation system has been performed by integrating the adjustable constraints protocol on the open platform Surgetics Station (PRAXIM-medivision, France), which uses image-free BoneMorphing technology. Based on navigated bone morphing the required preadjustment of the guide was done mechanically, with depth control by mini screws. Testings on 10 cadavers compared the planned vs. achieved positions of the jig before, after fixation, final implant position and planned vs. achieved cutting procedures.

Results: Results revealed for valgus/varus deviations before fixation −0.1°±0.7°, after 0.0°±0.8° (p=0.51), final implant position 0.9°±1.7° (p=0.93). For flexion before fixation −0.3°±1.3° after −0.3°±1.8° (p=0.44), final position 2.9°±2.5° (p=0.65). Distal cut height before fixation 0.0°±0.4°, after 0.1°±0.3° (p=0.61), final position 0.3°±1.0° (p=0.1). Axial rotation before −0.3°±1.1°, after fixation 0.2°±1.4° (p=0.57), final implant position 0.8°±2.7° (p=0.89). Anterior-posterior positions before fixation 0.7°±1.4°, after 1.0°±1.6° (p=0.27), final position 3.4°±1.3° (p=0.13). Highest deviations in the planned vs. actual cut position was found for the posterior cut −3.1°±2.4° in sagittal and anterior cut 0.8°±1.9° in the coronal plane. The highest mean errors in the final implant position where on the order of 3 degrees/mm in flexion and anterior-posterior positioning.

Conclusion: A novel ‘CAS-enabled 8 in 1 jig’ has been developed and validated. The system allows for direct execution of a complex, multi-planar CAS plan with single navigated device. The instrumentation is considerably simplified and eliminates the problems associated with sequential jigs.

Purpose: The goal of this prospective study was to evaluate the results of arthroscopic meniscal repair with the FasT-Fix repair system.

Type of study: Prospective case series.

Methods: 83 meniscal repairs with the FasT-Fix meniscal repair system in 80 patients with a mean age of 29 years were performed between 2001 and 2004. Concurrent anterior cruciate ligament (ACL) reconstruction was performed in 70% of the cases. 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 included also the Lyscholm knee score, and KT-1000 arthrometry.

Results: The average follow-up was 38 months (range, 24–61 months). Six of 83 repaired menisci (7.23%) were considered failures according to our criteria. Therefore, the success rate was 92.77%. Time required for meniscal repair averaged 15 minutes. Postoperatively, the majority of the patients had no restrictions in sports activities. 92% 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 one of them. Analysis showed that, age, length of tear, simultaneous ACL reconstruction, chronicity of injury, and location of tear did not affect the clinical outcome.

Conclusions: Our results, shows that arthroscopic meniscal repair with the FasT-Fix repair system provides a high rate of meniscus healing and offers reduction of both the risk of serious neurovascular complications and operative time.

Aim of study: Comparison of clinical and radiological results of the applied methods.

Material and method: 20 patients with osteochondritis dissecans of the talus were treated. Autologous chondrocyte transplantation was applied to a group of 10 patients (Group A) and autologous osteochondral transplantation to the rest 10 patients (Group B).Group A: Average-age=30,8 years, -follow up time= 33,6 (12–48) months, -lesion size= 20×16,2 (35–15 × 25–15) mm and depth =7 (20–5) mmGroup B: Average –age =33, 7 years, follow up time =32,4 (12–48) months, – lesion size=16,5×15 (25–10 × 20–10) mm and depth=4 (5–3) mm.All patients underwent clinical und radiological investigation and the symptoms were classified in accordance with the Finsen classification. Group A was treated with autologous chondrocyte and Group B with autologous osteochondral transplantation. Osteotomy of the medial or lateral malleolus was necessary by 6 Group A – patients and 4 Group B – patients. Postoperative treatment : Non-weight bearing for 6 weeks, continuous passive motion of the joint, clinical and radiological follow up 3rd, 6th, 12th and yearly basis

Results: Postoperatively the average Finsen score showed for Group A an improvement from 3,5 (very bad) to 1,1 (excellent) and for Group B from 3,6 (very bad) to 1 (excellent). MRI follow up showed defect coverage by 7 patients of Group A and 9 patients of Group B after 12 months. Second look arthroscopy was performed by 4 patient of Group A and 3 patients of Group B showing full coverage of the defect site. Complications: persisting swelling for an average time of 2,7 months in Group A and 4,3 months in Group B. Additionally 10 degrees loss of joint extension in 4 patients of Group A and 3 patients of Group B.

Conclusion: Autologous chondrocyte transplantation as well as autologous osteochondral transplantation present very good clinical results. As methods of articular surface restoration they have their advantages and disadvantages playing an important role in chosing one of them, in combination always with the surgeons philosophy. The existence of these methods is important in influencing the course of the ankle joint towards a good prognosis, in cases of osteochondral lesion. Further investigation is necessary.

Purpose of study: To investigate and compare the characteristics of the reconstructed articular surface microscopically and histologically after a time period of 6 weeks following the treatment of a focal defect of the right femoral head with subchondral drilling and autologous osteochondral transplantation in rabbits

Material and method: A 2,5 mm diameter and 3 mm depth iatrogenic osteochondral defect in the anterolateral weight bearing area of the right femoral head was created in 12 rabbits. In a group of 6 rabbits the lesion was treated with autologous osteochondral transplantation. The donor site for the transplant was the lateral condyle of the ipsilateral knee joint. The other group of 6 rabbits was treated with subchondral drilling. Both groups were sacrificed after a time period of 6 weeks and specimens were evaluated histologically under the classification system of the ICRS. For statistical analysis we used the Mann – Wittney test

Results: According to the ICRS score statistical significance was found for all variables between the 2 groups (subchondral drilling 6 weeks vs autologous osteochondral transplantation 6 weeks).: articular surface (p=0,049), matrix (p=0,003), cell distribution (p< 0,0005), subchondral bone (p=0,010), cartilage mineralization (p=0,0) except cell population viability.

Discussion: In comparison to subchondral drilling, autologous osteochondral transplantation provided better results concerning the smoothness and continuity of the articular surface, the consistency of the matrix with dominance of the hyaline and mixed hyaline – fibrocartilage type of tissue, the normality of subchondral bone and the columna r distribution of cells. The viability of the cell populations was the same for both methods. The incorporation of the osseous part of the graft was successful in all cases and the surgical procedure did not produce any necrosis of the femoral head.

Conclusion: In cases of focal osteochondral defect of the femoral head in rabbits, reconstruction of the articular surface through autologous osteochondral graft transplantation gives superior macroscopical and histological results in comparison to subchondral drilling

Purpose of study: To search and analyse the results of autologous osteochondral transplantation on patients with osteochondritis dissecans of the talus.

Material and method: From 1997 until 2000, 10 patients with 3dr to 4th degree osteochonditis dissecans of the taus were treated with autologous osteochondral transplantation. Their average: age was 33,7 years, and follow up time:32,4 months. Clinical evaluation in accordance with the Finsen classification system as well as radiological evaluation was conducted.

Afterwards arthroscopy with transplantation of autologous osteochondral grafts was performed. An osteomy of the medial malleolus was necessary by 4 patients. Non weight bearing and continuous passive motion for 6 weeks was advised.

Results: The average Finsen score showed improvement: From 3,6 preoperatively to 1 (excellent) postoperatively. Full coverage of the defects was observed at 12 month follow up with MRI in 9 patients and arthoscopically in 3 patients.

Conclusion: This method of treatment presents very good clinical results and sends a hopefull message on the prognosis of the ankle joint in cases of osteochondral damage.