Converting round tendons to flat tendon constructs: Does the preparation process have an influence on the structural properties?

PURPOSE: The structural properties of hamstring tendon grafts were evaluated in a porcine model, after processing it to a flat shape, to better replace or augment anatomic flat structures (e.g. ACL, MPFL or MCL). METHODS: In this biomechanical study, porcine flexor tendons were used which have a comparable shape to semitendinosus and gracilis tendons. One part of the tendon was prepared to a flat tendon construct by splitting the tendon longitudinally with a knife to half of the diameter of the tendon. The semi-split tendon was scratched out to a flat shape. The other matched part was tested in its original round shape. The tendons (n = 40) have been fixed in a uniaxial testing machine (Zwick/Roell) by cryo-clamps after preparing the fixed ends by 2-0 polyester sutures (2-0 Ethibond® EXCEL, Ethicon, Somerville, NJ). In every specimen, there was a free 60-mm tendon part between both clamps. The tendons have been loaded to failure to evaluate typical biomechanical parameters such as stiffness, yield load and maximum load. RESULTS: No statistically significant differences (n.s.) regarding stiffness, yield load and maximum load between natively round and processed flat tendons could be detected. CONCLUSION: A prepared flat-shaped tendon does not show any different structural properties compared with an original round tendon. Therefore, a flat tendon seems to be a biomechanical stable graft option for anatomic reconstruction or augmentation of injured natively flat-shaped structures such as MCL, MPFL or ACL.

Assessment of knee laxity using a robotic testing device: a comparison to the manual clinical knee examination.

PURPOSE: The purpose of this study was to collect knee laxity data using a robotic testing device. The data collected were then compared to the results obtained from manual clinical examination. METHODS: Two human cadavers were studied. A medial collateral ligament (MCL) tear was simulated in the left knee of cadaver 1, and a posterolateral corner (PLC) injury was simulated in the right knee of cadaver 2. Contralateral knees were left intact. Five blinded examiners carried out manual clinical examination on the knees. Laxity grades and a diagnosis were recorded. Using a robotic knee device which can measure knee laxity in three planes of motion: anterior-posterior, internal-external tibia rotation, and varus-valgus, quantitative data were obtained to document tibial motion relative to the femur. RESULTS: One of the five examiners correctly diagnosed the MCL injury. Robotic testing showed a 1.7° larger valgus angle, 3° greater tibial internal rotation, and lower endpoint stiffness (11.1 vs. 24.6 Nm/°) in the MCL-injured knee during varus-valgus testing when compared to the intact knee and 4.9 mm greater medial tibial translation during rotational testing. Two of the five examiners correctly diagnosed the PLC injury, while the other examiners diagnosed an MCL tear. The PLC-injured knee demonstrated 4.1 mm more lateral tibial translation and 2.2 mm more posterior tibial translation during varus-valgus testing when compared to the intact knee. CONCLUSIONS: The robotic testing device was able to provide objective numerical data that reflected differences between the injured knees and the uninjured knees in both cadavers. The examiners that performed the manual clinical examination on the cadaver knees proved to be poor at diagnosing the injuries. Robotic testing could act as an adjunct to the manual clinical examination by supplying numbers that could improve diagnosis of knee injury. LEVEL OF EVIDENCE: Level II.

The use of a robotic tibial rotation device and an electromagnetic tracking system to accurately reproduce the clinical dial test.

PURPOSE: The purpose of this study was to: (1) determine whether a robotic tibial rotation device and an electromagnetic tracking system could accurately reproduce the clinical dial test at 30° of knee flexion; (2) compare rotation data captured at the footplates of the robotic device to tibial rotation data measured using an electromagnetic sensor on the proximal tibia. METHODS: Thirty-two unilateral ACL-reconstructed patients were examined using a robotic tibial rotation device that mimicked the dial test. The data reported in this study is only from the healthy legs of these patients. Torque was applied through footplates and was measured using servomotors. Lower leg motion was measured at the foot using the motors. Tibial motion was also measured through an electromagnetic tracking system and a sensor on the proximal tibia. Load-deformation curves representing rotational motion of the foot and tibia were compared using Pearson's correlation coefficients. Off-axis motions including medial-lateral translation and anterior-posterior translation were also measured using the electromagnetic system. RESULTS: The robotic device and electromagnetic system were able to provide axial rotation data and translational data for the tibia during the dial test. Motion measured at the foot was not correlated to motion of the tibial tubercle in internal rotation or in external rotation. The position of the tibial tubercle was 26.9° ± 11.6° more internally rotated than the foot at torque 0 Nm. Medial-lateral translation and anterior-posterior translation were combined to show the path of the tubercle in the coronal plane during tibial rotation. CONCLUSIONS: The information captured during a manual dial test includes both rotation of the tibia and proximal tibia translation. All of this information can be captured using a robotic tibial axial rotation device with an electromagnetic tracking system. The pathway of the tibial tubercle during tibial axial rotation can provide additional information about knee instability without relying on side-to-side comparison between knees. The translation of the proximal tibia is important information that must be considered in addition to axial rotation of the tibia when performing a dial test whether done manually or with a robotic device. Instrumented foot position cannot provide the same information. LEVEL OF EVIDENCE: IV.

Double-bundle ACL reconstruction demonstrated superior clinical stability to single-bundle ACL reconstruction: a matched-pairs analysis of instrumented tests of tibial anterior translation and internal rotation laxity.

PURPOSE: To compare objective measures of in vivo joint laxity between patients treated with single-bundle (SB) or double-bundle (DB) anterior cruciate ligament (ACL) reconstructions. METHODS: Sixty-four patients matched by age, height, weight, and that had undergone unilateral SB or DB hamstring ACL reconstruction participated in this study. Bilateral anterior tibial translation (ATT) was recorded using the KT1000 arthrometer, and a robotic testing system was used to assess side-to-side differences in rotational characteristics. Each reconstruction was evaluated to determine how well it mimicked the anteroposterior (AP) and rotational biomechanics of the normal knee. A reconstruction was defined as mimicking the normal knee if ATT and internal rotation (IR) were within 3 mm and 3.5°, respectively. RESULTS: Side-to-side differences in ATT were significantly higher for the SB group (2.2 ± 1.4 mm) than the DB group (1.1 ± 1.0 mm, P = 0.001). While relative side-to-side differences in IR did not differ between the SB (1.3°) and DB groups (1.1°, P = 0.82), absolute IR differences were significantly less with the DB reconstruction (2.1° vs. 4.7°, P = 0.001). A significantly greater percentage of DB patients (81%, P = 0.0003) had both ATT and IR similar to the normal knee, compared to 34% of the SB patients; however, IKDC subjective scores did not differ between groups. Regardless of technique, patients with the greatest rotational laxity of their non-operative knee demonstrated significantly worse IKDC scores. CONCLUSION: DB reconstruction resulted in reduced side-to-side differences in both ATT and IR. The DB technique more consistently reproduced the biomechanical profile of the uninjured limb than did the SB technique without increasing the risk of over-constraining the knee.

A matched pairs comparison of single- versus double-bundle anterior cruciate ligament reconstructions, clinical results and manual laxity testing.

PURPOSE: To compare the subjective clinical results as well as manual anterior and rotational stability in patients treated with either single- (SB) or double-bundle (DB) anterior cruciate ligament (ACL) reconstructions. METHODS: Sixty-four patients who had undergone SB or DB hamstring ACL reconstruction with hamstrings were included in a retrospective matched pair analysis. At follow-up IKDC subjective, CKS, KOOS, CKS and a visual analogue satisfaction scale was assessed. A blinded surgeon examined the joint laxity and completed the objective IKDC. The KT-1000 was used to bilaterally test anterior tibial translation. Patients with confounding variables, which statistically influenced the clinical outcome (passive flexion and extension deficits, persistent quadriceps deficit, tibiofemoral osteoarthritis and non-repairable medial meniscus injury), were identified and excluded from the statistical analysis (n = 10). RESULTS: For all subjective scores, DB patients reported increased scores compared with SB patients. While consistently higher scores were demonstrated, statistical significance was only achieved for the IKDC subjective (P = 0.04) and VAS satisfaction (P = 0.02). Graded stability results of the Lachman, anterior drawer and pivot-shift tests were significantly higher in the DB group and KT-1000 side-to-side difference was significantly better for DB (P = 0.01). CONCLUSION: DB ACL reconstruction appeared to more consistently result in significantly higher subjective outcome scores and manual tests of joint stability than SB ACL reconstruction. Besides the surgical technique, normal extension and quadriceps strength after surgery were identified to be an essential component in order to provide the patient with a successful outcome.

Rotational laxity greater in patients with contralateral anterior cruciate ligament injury than healthy volunteers.

Rotational stability of the knee has been traditionally difficult to quantify, limiting the ability of the orthopedic community to determine the potential role of rotational laxity in the etiology of anterior cruciate ligament (ACL) injuries. The purposes of this multicenter cohort study were to evaluate the reliability of a robotic axial rotation measurement system, determine whether the uninjured knees of patients that had previous contralateral ACL reconstruction demonstrated different rotational biomechanical characteristics than a group of healthy volunteers, and determine whether knee rotational biomechanical characteristics differ between male and female non-injured limbs in groups of both healthy volunteers and patients with a previous contralateral ACL injury. Fourteen healthy volunteers and 79 patients with previous unilateral ACL injury participated in this study. Patients were tested using a computerized tibial axial rotation system. Only the normal (non-operated) knee data were used for analysis. In order to assess the reliability of the robotic measurement system, 10 healthy volunteers were tested daily over four consecutive days by four different examiners. Rotational laxity and compliance measures demonstrated excellent reliability (ICC = 0.97). Patients with a contralateral ACL injury demonstrated significantly increased tibial internal rotation (20.6° vs. 11.4°, P < 0.001) and reduced external rotation (16.7° vs. 26.6°, P < 0.001) compared to healthy volunteers. Females demonstrated significantly increased internal and external rotation, as well as significantly increased rotational compliance compared with males (P < 0.05). Computer-assisted measurement techniques may offer clinicians an accurate, reliable, non-invasive method to select the most appropriate preventative or surgical interventions for patients with increased knee rotational laxity.

[ACL reconstruction in skeletally immature patients]. / Ersatz des vorderen Kreuzbandes bei Kindern und Jugendlichen mit offenen Wachstumsfugen.

AIM: The treatment of choice for skeletally immature patients with anterior cruciate ligament (ACL) deficiency is an ACL reconstruction. In a retrospective study we analysed the clinical results after ACL reconstruction in skeletally immature patients. MATERIAL AND METHOD: In 55 immature patients the ACL was replaced with a four strand-hamstring graft in an anatomic transepiphyseal origin. The fixation was by means of an extracortical button femoral and a suture washer or staple tibial. Patient mean age at operation was 13 years (8 to 16 years). RESULTS: The mean follow-up was at 3.2 years (1 to 7.5 years) postoperatively. The objective IKDC 2000 score was 90.7 % normal or almost normal values. The mean Lysholm score was 94.1 points (70 - 100), the mean Cincinnati knee score was 93.9 points (76 - 100) and 88 % of the patients went back to normal or almost normal sports according to the Tegner score. Stability testing performed with the KT-1000 arthrometer was 1.0 mm (0 - 4 mm) (preoperative average 5.8 mm). The traumatic re-rupture rate was 5.5 %. In two additional cases a partial rupture of the graft was analysed by arthroscopy. Growth deformities or leg length differences were not seen in any case. CONCLUSION: ACL reconstruction with hamstrings and extracortical fixation showed good results and might be the treatment of choice in immature patients. The complication rate was low and there were no postoperative growth deformities.

Effect of severe exercise on plasma catecholamines in differently trained athletes.

OBJECTIVE: In the present study we investigated whether plasma catecholamine (CA) responses to short-term severe exercise (SX) are affected by different training regimen and whether this test will increase plasma catecholamine sulfates. METHODS: Nine anaerobically (ANTA) and eight aerobically trained male athletes (ATA) performed a severe treadmill exercise test (SX) at similar oxygen demands, leading to exhaustion within 2-3 min. RESULTS: The anaerobic contribution to energy supply was higher in ANTA than in ATA as indicated by the higher maximal accumulated oxygen deficit (37.5+/-3.5 vs. 22.7+/-4.4 mL x kg(-1) x min(-1)) (means +/- SE) (P<0.009) and blood lactate concentration after exercise (19.4+/-2.4 vs. 15.0+/-1.9 mmol x L(-1)) (P<0.005). In both groups plasma norepinephrine (NE), norepinephrine sulfate (NE-S), epinephrine (EPI), and epinephrine sulfate (EPI-S) increased significantly (P<0.05) during exercise with higher increments (P<0.05) in ANTA than in ATA (NE: 87.5+/-9.7 vs. 60.8+/-7.1 nmol x L(-1), P<0.034; EPI: 16.6+/-3.3 vs. 6.9+/-1.2 nmol x L(-1), P<0.009). CONCLUSION: Data suggest that during this type of exercise the sympathoadrenergic system is more activated in ANTA than in ATA and seems related to the higher anaerobic contribution to energy supply in ANTA. The short duration of SX was sufficient to increase plasma NE-S and EPI-S concentration.

[Unilateral blindness in neurosyphilis]. / Einseitige Erblindung bei Neurolues.

A 55 year-old patient developed loss of vision in his right eye over a period of a few weeks with the clinical finding of uveitis and papillaedema. Subsequently, also the left eye was affected by a marked deterioration of vision. The neurological findings were normal. The laboratory findings showed a marked elevation of the ESR (> 100 mm within the first hour) and protein electrophoreses showed changes suggestive of chronic inflammation. Analysis of the cerebrospinal fluid revealed a lymphocytic meningitis with 180/3 cells; the positive serological and liquor findings for TPHA and FTA led to the definite diagnosis of neurosyphilis. Treatment intravenously with 3 x 4 million units penicillin G daily for a fortnight proved curative. Vision of the left eye recovered fully, but the ophthalmological changes in the right eye were irreversible. This case shows that even today the differential diagnosis of syphilis must be considered with loss of vision of doubtful aetiology and uveitis.

Current concept of partial anterior cruciate ligament ruptures.

A partial tear of the anterior cruciate ligament is a frequent pattern of ACL injury, observed in 10 to 27% of isolated ACL lesions. There are three reasons to preserve these remnants: biomechanical, vascular and proprioceptive advantages for the patient. Good quality fibers work as graft protection during the healing process. Periligamentous and endoligamentous vessels present into the native ACL tissue may enhance the vascularization of the ACL augmentation. Mechanoreceptors still remaining in the residual ACL fibers may have proprioceptive function. Definition is controversial, based on anatomy, on clinical examination, on instrumental laxity assessment or on MRI findings. Continuous remnant ACL fibers bridging the femur and tibia, from native femoral ACL footprint to native tibial ACL footprint seem to be a good definition. Diagnostic is suspected by accumulation of arguments brought by a thorough clinical examination, precise MRI analysis and examination under anesthesia. But the final diagnostic needs an arthroscopic evaluation to confirm the presence of fibers in good position and to validate its good mechanical properties. The treatment of ACL partial tear is a demanding surgery; difficulties to visualize the graft insertion site, especially on the femoral side, require a perfect knowledge of the normal anatomy of the native ACL footprint. Adapted portals, perfect controls of the tunnel drilling process, intercondylar notch space management are the keys of success. The pivot shift test under anesthesia, a hard stop Lachman test, MRI findings, level and type of sport, arthroscopic aspects of the remnants and its mechanical properties, allow the surgeon decide between non operative treatment, ACL augmentation or standard ACL reconstruction.

[ACL reconstruction in skeletally immature patients]. / Ersatz des vorderen Kreuzbandes bei Kindern und Jugendlichen mit offenen Wachstumsfugen.

AIM: The treatment of choice for skeletally immature patients with anterior cruciate ligament (ACL) deficiency is an ACL reconstruction. In a retrospective study we analysed the clinical results after ACL reconstruction in skeletally immature patients. MATERIAL AND METHOD: In 55 immature patients the ACL was replaced with a four strand-hamstring graft in an anatomic transepiphyseal origin. The fixation was by means of an extracortical button femoral and a suture washer or staple tibial. Patient mean age at operation was 13 years (8 to 16 years). RESULTS: The mean follow-up was at 3.2 years (1 to 7.5 years) postoperatively. The objective IKDC 2000 score was 90.7 % normal or almost normal values. The mean Lysholm score was 94.1 points (70-100), the mean Cincinnati knee score was 93.9 points (76-100) and 88 % of the patients went back to normal or almost normal sports according to the Tegner score. Stability testing performed with the KT-1000 arthrometer was 1.0 mm (0-4 mm) (preoperative average 5.8 mm). The traumatic re-rupture rate was 5.5 %. In two additional cases a partial rupture of the graft was analysed by arthroscopy. Growth deformities or leg length differences were not seen in any case. CONCLUSION: ACL reconstruction with hamstrings and extracortical fixation showed good results and might be the treatment of choice in immature patients. The complication rate was low and there were no postoperative growth deformities.

Tibial bone bridge and bone block fixation in double-bundle anterior cruciate ligament reconstruction without hardware: a technical note.

Current techniques for tibial graft fixation in four tunnels double bundle (DB) anterior cruciate ligament (ACL) reconstruction are by means of two interference screws or by extracortical fixation with a variety of different implants. We introduce a new alternative tibial graft fixation technique for four tunnels DB ACL reconstruction without hardware. About 3.5 to 5.5 cm bone cylinder with a diameter of 7 mm is harvested from the anteromedial (and posterolateral) tibial bone tunnel (s) with a core reamer. The anteromedial (AM) and posterolateral (PL) hamstring tendon grafts (or alternatively tendon allografts) are looped over an extracortical femoral fixation device and cut in length according to the total femorotibial bone tunnel length. The distal 3 cm of each, the AM- and PL bundle graft are armed with two strong No. 2 nonresorbable sutures and the four suture ends of each graft are tied to each other over the 2 cm wide cortical bone bridge between the tibial AM and PL bone tunnel. In addition the AM- and/or PL bone block which was harvested at the beginning of the procedure is re-impacted into the two tibial bone tunnels. A dorsal splint is used for the first two postoperative weeks and physiotherapy is started the second postoperative day. The technique is applicable for four tunnels DB ACL reconstruction in patients with good tibial bone quality. The strong fixation technique preserves important tibial bone stock and avoids the use of tibial hardware which knows disadvantages. It does increase tendon to bone contact and tendon-to-bone healing and does reduce implant costs to those of a single bundle (SB) ACL reconstruction. Revision surgery may be facilitated significantly but the technique should not be used when bony defects are present. In case of insufficient bone bridge fixation or bone blocks hardware fixation can be applied as usual.

Posterior stability in fixed-bearing versus mobile-bearing total knee replacement: a radiological comparison of two implants.

INTRODUCTION: Posterior tibial translation in total knee replacement (TKR) could be one major factor for PE wear, delamination and loosening of the tibial component due to increased shear forces and component-to-bone interface stress. The aim of this study was to assess the posterior stability of two different designs of posterior cruciate ligament (PCL) substituting TKR. METHOD: In this non-randomised consecutive study 43 patients underwent TKR for primary osteoarthritis. Twenty-six patients in group FB received a deep-dished fixed-bearing Duracon TKR (Howmedica, Rutherford, NJ, USA) and 17 patients in group MB a deep-dished rotating mobile-bearing Duracon TKR. In both groups the PCL was resected. All patients had pre- and postoperative kneeling stress radiographs and were clinically evaluated with the Knee Society Score. Posterior tibial translation was measured by tracing a line along the posterior tibial cortex in relationship to the posterior edge of Blumensaat's line. RESULTS: The average follow-up was 13 months for group FB and 11 months for group MB. Both groups demonstrated a statistical significant increase of the mean posterior tibial translation on kneeling stress X-ray of 4.1 mm (group FB) (P < 0.001) and of 6.6 mm (group MB) (P < 0.001) compared to pre-operative. Group MB showed a significant higher posterior draw (P < 0.008). Clinical assessment using the Knee Society Score showed comparable short-term results. CONCLUSION: The deep-dished fixed-bearing TKR as well as the deep-dished rotating mobile-bearing TKR demonstrated significant posterior tibial translation on kneeling stress X-ray. It remains to be determined what amount of joint play is optimal for clinical function and to minimise shear forces and PE wear. Moreover the amount of posterior tibial translation was significantly higher with the mobile-bearing insert, which could be directly related to the asymmetric rotational mobility of the tibial insert. A long-term follow-up is necessary to investigate whether our findings correlate with the survival-rate of these specific implants.

Assessment of posterior stability in total knee replacement by stress radiographs: prospective comparison of two different types of mobile bearing implants.

The aim of this study was to assess the posterior stability of two different designs of total knee replacement (TKR) with deep-dished mobile bearing (MB) implants using stress X-rays. In a prospective non-randomized consecutive study, 34 patients with primary osteoarthritis of the knee underwent TKR. In group A (17 knees), they received a MB insert with a Duracon prosthesis and in group B (18 knees), a Genesis prosthesis. In all cases the posterior cruciate ligament (PCL) was resected. All patients had pre- and post-operative kneeling X-rays and were clinically evaluated with the Knee Society Score. Measurements on the radiographs were taken by tracing a line along the posterior cortex of the tibia and then measuring the perpendicular distance to a point marked at the posterior corner of Blumensaat's line. The average follow up was 10.7 months for group A and 5.4 months for group B. No statistical difference could be found in terms of clinical results and pre- and post-operative kneeling X-rays between the two groups. In each group, all knees demonstrated a significant posterior tibial translation postoperatively compare to their pre-operative status (p<0.0001). There are advantages in resecting the PCL in TKR: mobile flexion gap, correction of fixed deformity, more flexibility to adjust the joint line. The use of a deep dished polyethylene (PE) insert provides stability and use of MB insert reduces PE wear whilst retaining congruity. Two designs of deep-dished MB inserts showed significant posterior tibial translation on stress X-rays. It remains to be determined what amount of laxity is optimal for clinical function and polyethylene longevity.

Combination of microfracture and periostal-flap for the treatment of focal full thickness articular cartilage lesions of the shoulder: a prospective study.

Focal full-thickness articular cartilage lesions of the shoulder are less common than those of the lower extremity but are often symptomatic and may progress to degenerative osteoarthritis. This prospective study evaluated our clinical results for cartilage repair in five patients with chondral defects localized at the humeral head using a combination of microfracture and periostal flap, all by deltoidopectoral approach. Mean follow-up was 25.8 months (range 24-31) and consisted of a clinical examination, Constant score examination, radiography, and magnetic resonance imaging; three patients underwent a second-look arthroscopy an average of 8 months following cartilage repair. We found the Constant score significantly improved over the preoperative level, from 43.4% to 81.8%. Pain was reduced significantly to 18.6 points. Radiography and magnetic resonance imaging showed progression of the osteoarthritis in two patients. Second-look arthroscopy revealed a significantly reduced cartilage lesion. This is the first report of a combination of microfracture and a periostal flap for repair of focal full-thickness cartilage lesions at the shoulder. Short-term follow-up clinical results were satisfactory. It is essential to address the underlying pathology. Results must be reconfirmed in a long-term study.

[Primary- and revision-reconstruction of the anterior cruciate ligament with allografts: a retrospective study including 325 patients]. / Allogene Transplantate zur Rekonstruktion des vorderen Kreuzbandes bei Primär- und Revisionseingriffen.

UNLABELLED: At our institution we have used fresh-frozen allografts for the reconstruction of the anterior and posterior cruciate ligament since 1993. METHOD: In this retrospective study we evaluated the clinical outcome of 325 fresh-frozen allografts (bone-patellar-tendon-bone allografts and Achilles-bone-tendon allografts) for primary and revision ACL-reconstruction. Patients (average age 38 years) were operated between 5/1993 and 2/1998 and mean follow-up was 38 (range 24 to 71) months. Clinical evaluation consisted of a case history, an examination, IKDC, Cincinnati knee score (CKS), KT-1000 testing and standardized X-rays. RESULTS: Overall subjective rating according to the CKS was more than 82 points for both groups. Objective results according to the IKDC were normal or nearly normal in 75.6 % of primary- and 67.0 % of revision-ACL reconstructions. The stability measured with the KT-1000 showed an average maximum side to side difference of 2.1 mm for primary ACL reconstruction and 2.3 mm for revisioners. The total failure-rate (= rerupture-rate + laxity-failures) was 13.7 % for primary and 15.0 % for revision ACL reconstructions. CONCLUSION: Given the increased failure-rate, autograft tissue remains our graft of first choice for primary ACL-reconstruction. We advise to reserve allografts for revision procedures where suitable autogenous tissues have been previously compromised, where a contraindication for autogenous tissue harvest exists or for multiple ligament surgery. No specific complications were observed with the use of allograft tissue.

A new bicortical tibial fixation technique in anterior cruciate ligament reconstruction with quadruple hamstring graft.

We report a prospective series of 101 patients receiving a four-strand semitendinosus-gracilis autograft for anterior cruciate ligament reconstruction using a new bicortical tibial fixation technique with bioabsorbable interference screws. Patients (average age 32 years) were operated on between November 1997 and Mai 1998, and follow-up was at least 12 months postoperatively. The evaluation consisted of history, clinical examination, IKDC score, Cincinnati Knee Score, KT-1000 testing, standardized radiography and magnetic resonance imaging. One hundred patients were available for follow-up. There were two traumatic reruptures 6 and 11 months postoperatively. By IKDC score 87 patients were in groups A and B, 12 in group C, and 2 with a rerupture in group D. Mean Cincinnati Knee Score was 82 (range 46-100), KT-1000 manual maximum at follow-up showed an average difference of 1.7 mm between the sides. Full extension was rapidly achieved in all cases, and flexion averaged 135 degrees . Considering the enlargement caused by the bioabsorbable interference screws, the incidence of tunnel widening was 6.6% on the femoral side and 1.7% on the tibial side. Tunnel widening did not affect the clinical results. Three patients experienced an effusion after more than 6 months postoperatively. There was one infection, which settled without functional impairment after early arthroscopic lavage and intravenous antibiotics. Otherwise no complications occurred. The described technique for anterior cruciate ligament reconstruction combines the advantage of anatomical graft position with sufficient graft fixation. A short intra-articular graft construct with a strong tendon to bone interface was created. Clinically, 87% of patients had a normal or nearly normal IKDC score at follow-up. Magnetic resonance imaging revealed a considerable increase in tunnel area caused by the insertion of the interference screws. On the other hand, the development of a "fibrous interzone" between the graft and the bone tunnel was prevented in most cases. At short-term follow-up the bicortical tibial fixation proved to be efficient even with an aggressive rehabilitation program.

[Long-term results with the cement-free Spotorno CLS shaft]. / Langzeitergebnisse mit dem zementfreien CLS-Schaft von Spotorno.

This retrospective study reviews 298 sequential cementless CLS Spotorno stems, which achieved their primary fixation and bony in- or ongrowth predominantly in the metaphyseal region. The minimum follow-up was 10 years and the average follow-up 11.7 years (range 10-14). The mean age at surgery was 55.2 years (range 32.2-68.9). Of the patients, 76.2% (227 stems) were followed up: 172 patients (57.7%) underwent clinical and radiological examination and 52 patients (55 stems, 18.5%) were interviewed by telephone. Of 298 stems, 13 (4.4%) had been replaced in the mean time, only 6 stems (2.0%) because of an aseptic loosening. The evaluation included both clinical (Merle d'Aubigne and Harris hip score) and radiographic parameters (plain X-rays). The mean Merle d'Aubigne score was 16.7 points, and the mean Harris hip score was 94.3 points. Radiolucent lines were detected in 33.7%; 5.8% showed enlargement within the last 3 years. Focal osteolyses were present in 30.8% of patients; 2.9% had progressed within the last 3 years. At follow-up, one patient presented with new clinical and radiological evidence of aseptic stem loosening. The current study showed an aseptic loosening of the CLS stem in 2.3%, a good osseointegration and good functional score results in more than 90%. The primary fixation and bony in- or ongrowth predominantly in the metaphyseal region seems to achieve good clinical results. Wear is the main reason for the osteolytic changes. Frequent clinical and radiological follow-up is important to detect bone reactions and loosening of the stem.

Clinical evaluation of meniscus repair with a bioabsorbable arrow: a 2- to 3-year follow-up study.

In a clinical study with the bioabsorbable Bionx Meniscus Arrow we prospectively evaluated 113 consecutive patients (113 menisci) after all-inside meniscus repair. Repairs were performed in either the medial (80.5%) or lateral (19.5%) posterior horn in the red-red or red-white meniscal zone; 66% of patients underwent concomitant ACL reconstruction. Assessment was based on history, clinical examination, and Lysholm [37] and Cincinnati Knee Scores. After a mean follow-up was 33 months (range 24-43; n=105) 21 (20%) patients showed signs and symptoms consistent with a meniscus tear (16 medial, 5 lateral) and underwent partial meniscectomy. In 11 (52%) of the revised patients concomitant ACL reconstruction was performed; 4 (19%) of revised patients were older than 35 years. In the nonrevised the average Lysholm Score was 92.5 and the average Cincinnati Score 90.4. Two patients showed a distinct femoral cartilage damage. Patient's age did not significantly affect the revision rate. Meniscus repair with the bioabsorbable arrow leads to clinical results comparable to those of traditional suture techniques. When stabilized, patients with concomitant ACL reconstruction showed comparable results to patients without ACL rupture. The simple and time saving all-inside insertion obviates the need for additional incisions and avoids knot tying. A proper tear selection and arrow positioning is necessary and should avoid cartilage damage.

A prospective evaluation of tunnel enlargement in anterior cruciate ligament reconstruction with hamstrings: extracortical versus anatomical fixation.

Changes in the femoral and tibial bone tunnel were studied prospectively after arthroscopic ACL reconstruction with quadruple hamstring autograft. To determine whether tunnel enlargement can be decreased by fixing the graft close to the joint line having a stiffer fixation construct we compared "anatomical" (one absorbable interference screw femorally, and bicortical fixation with two absorbable interference screws tibially) and extracortical fixation techniques (Endobutton femorally, and two no. 6 Ethibond sutures over a suture washer tibially). Over a 2-year period we evaluated 60 patients clinically (IKDC scale, Cincinnati Knee Score, KT-1000) and radiographically (confirmed by MRI). The operated knee was radiographed immediately postoperatively and 6 and 24 months postoperatively. The femoral and tibial bone tunnel diameter was measured on anteroposterior and lateral images, and the tunnel area was calculated and compared to the initial area calculated from the perioperative drill size. In the "anatomical" group the immediately postoperative bone tunnel area was 75% larger than the initial tunnel area, after 6 months it was increased another 31%, and between 6 and 24 months it remained basically unchanged. In the "extracortical" group there was no significant enlargement immediately postoperatively, but after 6 months it was 65% larger than the initial area of drill and graft size, and between 6 and 24 months it decreased to 47%. There was no correlation between the amount of tunnel enlargement and clinical scores or KT-1000 measurement. Arthroscopic ACL reconstruction with quadruple hamstring autograft is associated with bone tunnel enlargement. Using a purely extracortical fixation technique thus significantly increased the tibial and femoral tunnel area during the first 6 postoperative months, while it decreased slightly thereafter. The insertion of large interference screws apparently not only compresses the graft in the bone tunnel but also significantly enlarges the bone tunnel itself. The immediate enlargement at the time of the operation is followed by a reduced further enlargement at 6 months and then stabilization. Tunnel widening did not influence clinical outcome over a 2-year period.