A. Gächter

Arthroscopic management of septic arthritis: stages of infection and results

Seventy-six patients with septic arthritis (78 affected joints) were treated with a combination of arthroscopic irrigation, débridement, and antibiotic therapy according to the tested bacterial sensitivity. There were 62 knee, 10 shoulder, 5 ankle joints, and 1 hip joint. No antibiotics were added to the irrigating solution. The arthroscopic and radiological stage of infection, treatment, and outcome in these patients was analyzed. The patients were classified into three groups according to initial stage of joint infection (stage I: 21 patients, 22 joints; stage II: 43 patients, 44 joints; stage III: 12 patients, 12 joints). Causes of infection were: hematogenous dissemination in 54%, postoperative wound infection in 28% (17% after open, 11% after arthroscopic procedures). Other causes were: 10% intra-articular steroid injections, 3% diagnostic punctures, and 3% open traumatic injury of the joint. In 78% of the infected joints the causative organism could be identified: Staphylococcus aureus was the most common organism found (42%), followed by streptococci (15%), pneumococci (6%), Escherichia coli (4%), Staphylococcus epidermidis (3%), Borrelia burgdorferi (3%), and others in 5%. In the stage I group only one patient needed repeated arthroscopic irrigation, in the stage II group 52%, and in the stage III group 75%. Open revision for eradication of the infection was necessary in one joint with stage II and in two joints with stage III infection (3%). Two joints of the stage III group needed additional surgery after successful treatment of the infection. The combination of arthroscopic irrigation and systemic antibiotic therapy was able to cure 91% of the affected joints. Open revision was necessary in 4% of joints. The number of arthroscopic procedures and the efficacy of treatment depended on the initial stage of the infection. It is concluded that an arthroscopic staging of the initial joint infection has prognostic and therapeutic consequences.

The benefits of wearing a compression sleeve after ACL reconstruction.

PURPOSE It was the purpose of the present study to examine the possibility of increased muscle coordination after anterior cruciate ligament (ACL) reconstruction through the wearing of a compression sleeve. METHODS Thirty-six patients were studied who had undergone unilateral ACL reconstruction at least 12 months previously. All subjects were required to perform a 10-cm standing drop jump from an elevated platform onto a force plate, to land on one leg, and thereafter maintain a one-legged balance for 25 s. This task was repeated three times without and three times with an elastic compression sleeve worn on the reconstructed limb. For analysis, the task was partitioned into a landing phase (150 ms), an adjusting phase (10s), and a balancing phase (10s). The peak impact loadings were measured in each direction (Fx, Fy, and Fz) during landing, while force-time integrals (intFz, intFy, and intFz) and root mean square (RMS) error of these forces were calculated for the adjusting and balancing phases. The path length and RMS of the center of pressure coordinates (Ax and Ay) were obtained for the adjusting and balancing phases combined. RESULTS Drop landings with the bandage produced significantly larger (P < 0.001) peak ground reaction forces in the vertical and anteroposterior direction, suggesting increased subject confidence in their knee. Wearing the knee bandage also enabled the patients to reduce all measured parameters in the anteroposterior direction (rmsFx, intFx, rmsAx) during both the adjusting and balancing phases (P < 0.001 ). A significant reduction in the center of pressure path length further indicated an enhanced steadiness during the one-legged stance. CONCLUSIONS It was concluded that a compression sleeve improved the total integration of the balance control system and muscle coordination.

Isolated and Combined Tears of the Subscapularis Tendon

Background Isolated and combined subscapularis tendon tears are rare and are described in the literature only in small numbers. Hypothesis The outcome of surgical intervention for isolated and combined subscapularis tendon tears may be influenced by the tear pattern of the anterior rotator cuff and the period of time between trauma and surgical procedure. Study Design Case series; Level of evidence, 4. Methods Between 1994 and 1999, 34 shoulders with isolated traumatic tears (16 shoulders) or subscapularis tendon rupture combined with a supraspinatus tendon tear were treated operatively. The average patient age was 51 years, and the mean follow-up period was 37 months. For statistical analyses, the Friedman and Mann-Whitney tests were used. Results In patients with isolated tears, the Constant score rose from an average of 43.9 to 88.7 points (P <. 01), and in patients with combined tears, it rose from an average of 40.6 to 74.7 points (P <. 01). Isolated tears improved 14 points more than combined tears (P <. 05). The delay between trauma and surgical intervention was inversely proportional to the improvement in the Constant score. The Spearman coefficient of correlation was -0.97 in isolated tears and -0.89 in combined tears. Conclusions Young patients with isolated traumatic tears of the subscapularis tendon and immediate repair have the best prognostic factors for treatment. Accuracy in the trauma history and the clinical and radiographic examination is demanded.

Anterior cruciate ligament reconstruction combined with valgus tibial osteotomy (combined procedure).

We assessed the patients who were operated on in a combined procedure from 1980 to 1992 with anterior cruciate ligament (ACL) insufficiency, cartilaginous lesions of the medial compartment, lesion of medial meniscus and varus malalignment. The combined operative procedure was autologous intra-articular ACL reconstruction with the middle third of the patellar ligament-partially augmented with Kennedy-ligament augmentation device (LAD) in hot dog technique-and high tibial osteotomy. The patients were examined according to the criteria of IKDC including testing of anterior stability with the KT-1000 arthrometer. Radiographically we checked axis and arthritis according to a modified score of Kannus. Twentyseven of 34 patients who fulfilled the inclusion criteria could be followed up in three categories (2–5 years postoperatively, 5–10 years postoperatively, over 10 years postoperatively). Total qualification was good in 37%; there were no perioperative complications. Rehabilitation was not prolonged. Eighty-nine percent practised their prcoperative job, over 50% had a higher level of sports activities than preoperatively, and more than 25% regained their pretraumatic sports capacity. Two-thirds had no giving way and less than 3 mm translation difference in comparison to the contralateral knee. Seventy-five percent of patients would accept the operation again. Radiological findings had no correlation to overall qualification. The encouraging results with respect to many of the criteria suggest using the combined procedure in a young patient with ACL insufficiency, varus malalignment and medial compartment damage including medial meniscus lesion.ZusammenfassungIm Sinne einer Qualitätskontrolle wurden die von 1980 bis 1992 an der orthopaedisch-traumatologischen Abteilung des Kantonsspitals Basel einzeitig operierten Patienten bei vorderer Kreuzbandinsuffizienz. medialem Knorpelschaden, medialer Meniskuslaesion und Varusmorphotyp nachuntersucht. Es handelt sich um einen Kombinationseingriff von vorderer intraartikulaerer Kreuzbandersatzplastik mit mittlerem Drittel des Ligamentum patellae-z.T. augmentiert mit einem LAD Band nach Kennedy in hot dog Technik-und Achsenkorrektur der proximalen Tibia. Die Patienten wurden gemäß Richtlinien des IKDC klinisch nachuntersucht und zusätzlich apparativ die Stabilität mittels KT-1000-Arthrometer untersucht und radiologisch Achsen und Arthrose nach Kannus bestimmt. Zusatzfragen wurden anhand eines Fragebogens beantwortet. 27 von 34 die Einschlußkriterien erfüllenden Patienten (79%) konnten in 3 Kategorien (2–5 Jahre postoperativ, 5–10 J. postop und über 10 J. postop) nachuntersucht werden. Die Gesamtqualifikation war gut bei 37%, peri- und frühpostoperative Komplikationen fehlten, die Dauer der Rehabilitation war nicht verlängert, 89% gingen dem praeoperativ ausgeübten Beruf nach, über die Hälfte der Patienten konnte die sportliche Aktivität gegenüber praeoperativ steigern und 1 Viertel sogar die Sportaktivität vor dem Unfall wiedererlangen und die subjektive (2/3 ohne Giving way) und objektive Stabilität (2/3 bis 3 mm Translationsdifferenz zur gesunden Seite) der operierten Kniegelenke war gut. Drei Viertel der Patienten würden sich den Eingriff wieder durchführen lassen. Die radiologischen Ergebnisse korrelieren nicht mit der Gesamtqualifikation. Die ermutigenden Nachkontrollergebnisse hinsichtlich vieler kontrollierter Kriterien sprechen für das einzeitige Verfahren beim jüngeren Patienten mit vorderer Instabilität, Varusmorphotyp und medialem Kompartimentsschaden inklusive medialer Meniskuslaesion anstelle der Durchführung nur eines Eingriffs oder beider mit Intervall.

Spin-echo and 3D gradient-echo imaging of the knee joint: a clinical and histopathological comparison

OBJECTIVE A clinical and histopathological comparison of 2D spin-echo (SE) and 3D gradient-echo (3DGE) sequences was undertaken for the knee joint. The purpose of the study was to evaluate the clinical results and to explain the different appearances of meniscal abnormalities on both 2DSE and 3DGE images. PATIENTS, MATERIALS AND METHODS The clinical study comprised 45 patients with arthroscopically correlated MR imaging results. For the histopathological correlation, seven cadaveric knee joints were examined with the same 2DSE and 3DGE (FISP) imaging protocol and sliced in sagittal sections according to the MR images. Different stainings were used. RESULTS For the detection of meniscal tears, accuracy (82.2%) and positive predictive value (70.7%) of the 3DGE sequence were limited due to a high number of false positive findings. Cartilaginous lesions were more easily visible on 3DGE than on 2DSE images (sensitivity: 63.1% vs. 52.6%, respectively). As in the clinical study, the meniscal signal abnormalities of the cadaveric knee joints were much more extensive on the 3DGE images than on the 2DSE images. The 3DGE findings correlated better with degenerative meniscal changes which were visible microscopically. CONCLUSION The high sensitivity of the 3DGE sequence for degenerative meniscal changes explains the lack of specificity for the differentiation between meniscal degeneration and tears with this sequence. The MR grading system for meniscal lesions is of limited value for the evaluation of 3D FISP images.

Oblique screws at the plate ends increase the fixation strength in synthetic bone test medium

Objective: To test the hypothesis that oblique screws at the ends of a plate provide increased strength of fixation as compared to standard screw insertion. Design: Biomechanical laboratory study in synthetic bone test medium. Methods: Narrow 4.5-mm stainless steel low-contoured dynamic compression plates were anchored with cortical screws to blocks of polyurethane foam. The fixation strength in cantilever bending (gap closing mode) and torsion was quantified using a material testing system. Different constructs were tested to investigate the effect of the screw orientation at the end of the plate (straight versus oblique at 30°), the plate, and bridging length as well as the number of screws. Results: An oblique screw at the plate end produced an increased strength of fixation in all tests; however, the difference was more significant in shorter plates and in constructs with no screw omission adjacent to the fracture site. Both longer plates and increased bridging length produced a significantly stronger construct able to withstand higher compression loads. Under torsional loading, the fixation strength was mainly dependent on the number of screws. Conclusions: The current data suggest that when using a conventional plating technique, plate length is the most important factor in withstanding forces in cantilever bending. With regard to resisting torsional load, the number of screws is the most important factor. Furthermore , oblique screws at the ends of a plate increase fixation strength.

Comparison of total and partial traumatic tears of the subscapularis tendon

We treated surgically 16 shoulders with an isolated traumatic rupture of the subscapularis tendon over a six-year period. Nine patients had a total and seven a partial tear of the subscapularis tendon. Repair was undertaken through a small deltopectoral groove approach. The mean Constant score improved in total tears from 38.7 to 89.3 points (p = 0.003) and in partial tears from 50.7 to 87.9 points (p = 0.008). The total tears were significantly more improved by surgery than the partial tears (p = 0.001). The delay between trauma and surgery was inversely proportional to the improvement in the Constant score suggesting that early diagnosis and surgical repair improves outcome.

Knieendoprothetik – Sportorthopädische Möglichkeiten und Einschränkungen

ZusammenfassungPatienten möchten sich nach einer Knieprothese häufig wieder sportlich betätigen. Die bisherigen Empfehlungen basieren jedoch auf dem Gefühl des Orthopäden und nicht auf wissenschaftlich fundierten Daten. Jede sportliche Aktivität bewirkt im Gelenk einen zusätzlichen Abrieb, was die Lebensdauer einer Prothese negativ beeinflussen kann. Um diesen Abrieb möglichst gering zu halten, sollten sportlichen Aktivitäten eine geringe Spannung auf dem Polyethylen Inlay hervorrufen.Die folgende Arbeit versucht anhand der Literatur sowie biomechanischer Überlegungen sportliche Aktivitäten mit möglichst geringen Belastungen des Inlays zu finden. Beim Gehen auf der Ebene können Kniegelenkskräfte von 3- bis 4-mal Körpergewicht bei 20 ° Knieflexion auftreten. Beim abwärts Gehen steigen die Gelenkkräfte aufs 8 fache des Körpergewichts bei 40 ° Knieflexion.Beim Fahrrad Fahren besteht eine Kniegelkenksbelastung von 1,2-mal Körpergewicht bei 80 ° und beim langsamen Joggen 8- bis 9-mal Körpergewicht bei 50 ° Knieflexion. Wegen der Geometrie der Femurkomponente spielt beim Kniegelenk, im Gegensatz zur Hüftprothese, auch der Flexionswinkel für die Kontaktfläche und die Inlay Spannung eine große Rolle. So kann eine Knieprothese extensionsnahe stärker belastet werden als in starker Flexion.Aktivitäten wie Joggen produzieren sehr hohe Inlayspannungen und sollten nach einer Knieprothese gemieden werden. Auch abwärts Gehen produziert wegen der grossen Gelenkkraft und des Flexionswinkels hohe Inlay Spannungen. Beim Wandern sollten sich die Patienten auf das aufwärts Gehen beschränken und abwärts die Bahn benutzen. Falls die Patienten dennoch abwärts gehen müssen, sollten unbedingt Stöcke zur Entlastung gebraucht werden. Dies bringt eine Reduktion der Kniegelenksbelastung bis zu 20 %. Weiter empfiehlt sich ein Verzicht auf Abkürzungen sowie langsames Gehen. Fahrradfahren oder Power-Walking scheinen geeignete Sportaktivitäten nach einer Knieprothese zu sein.AbstractMany patients would like to resume some sport activities after total knee replacement; however, most recommendations are based on subjective opinion rather than scientific evidence.The following paper presents a literature review of sports after total knee replacement and includes recommendations which are based on biomechanical laws. Most total knee designs show increased conformity near full extension. Beyond a certain knee flexion angle, the conformity ratio decreases due to a reduced femoral radius. Therefore, these designs accept higher loads near full extension than in flexion. In order to recommend suitable physical activities after total knee replacement, both the load and the knee flexion angle of the peak load must be considered. It has been shown that power walking and cycling produce the lowest polyethylene inlay stress of a total knee replacement and seem to be the least demanding endurance activities.Jogging and downhill walking show high inlay stress levels and should be avoided. Hence, for mountain hiking, patients are advised to avoid descents or at least use ski-poles and walk slowly downhill to reduce the load on the knee joint. It must also be mentioned that any activity represents additional wear, which may affect the long-term results of total knee replacements. Further clinical studies are necessary to validate the biomechanical investigations.

Comparison of augmented and non-augmented anterior cruciate ligament reconstruction combined with high tibial osteotomy.

In a follow-up study 27 patients were evaluated after anterior cruciate ligament (ACL-)reconstruction combined with high tibial osteotomy because of chronic rupture of the ACL, cartilaginous lesions of the medial compartment and varus malalignment. They were divided into two groups. In 14 patients (non-LAD group) ACL reconstruction was performed using the central third of the autologous patellar tendon modified according to Eriksson-Trillat. Thirteen patients (LAD group) underwent repair with the same technique, but a Kennedy ligament augmentation device (LAD) in ‘hot dog’ technique and fixed over the top was added. The postoperative treatment was the same in both groups. All patients were examined according to IKDC criteria. KT-1000 arthrometer testing at maximum manual traction was performed. Although the mean follow-up interval was more than double in the non-LAD group (non-LAD: 127 months vs LAD: 58 months), the subjective and clinical results, IKDC evaluation and KT-1000 arthrometer testing results were similar, showing no statistically significant difference. Further, no complications due to the use of LAD occurred. In this study no evident functional or clinical advantage from the augmentation performed could be shown.

Die arthroskopische Meniskusrefixation mit Biofix®-Meniskusankern – eine Alternative?

In einer nicht vergleichenden Studie werden die klinischen Ergebnisse nach arthroskopischer Meniskusrefixation mit Biofix®-Ankern dargestellt und kritisch diskutiert.Von August 1996–Oktober 1998 wurde konsekutiv bei 45 Patienten (28 männlich, 17 weiblich, 45 Meniskusrisse), mit einem Durchschnittsalter von 25,8 Jahren (11– 61 Jahren) eine Meniskusrefixation mit Biofix®-Meniskusankern (Bionx Implants, Tampere) bei refixierbaren, randständigen Meniskuslängsrissen durchgeführt. Es handelte sich um 29 mediale und 16 laterale komplette periphere Risse länger als 10 mm. 22 Patienten hatten eine assoziierte vordere Instabilität, wovon 11 zur gleichen Zeit rekonstruiert wurden, 2 verzögert. 19 Menisken wurden später als 6 Wochen nach Trauma versorgt. 41 Menisken wurden nur mit Biofix®-Ankern fixiert, 4 zusätzlich mit outside-in-Nähten.Es kam zu keinen neurovaskulären Komplikationen oder Infektionen. Postoperativ zeigten 8 Patienten einen temporären Gelenkerguss (in den ersten 12 Wochen) und 4 Patienten eine mechanische Irritation der Kapsel, bedingt durch zu lang gewählte Anker. Im Follow-up zeigten 9 Patienten (4 mediale Korbhenkel, 4 Innenmeniskushinterhörner, ein lateraler Korbhenkel) positive Meniskuszeichen bzw. Blockaden. Die Second-look-Arthroskopie (n = 9, im Schnitt 4,6 Monate nach Refixation) bestätigte, dass der Meniskus nicht angeheilt war (n = 8) bzw. einmal nach adäquatem Trauma rerupturiert war. Reste der resorbierbaren Anker waren nicht sichtbar. Vier dieser Patienten hatten ein instabiles Kniegelenk, so dass die Fehlerrate in stabilen Kniegelenken bei 14% (5 von 36 Menisken) liegt. Bei 8 dieser Versager war eine Meniskusteilresektion erforderlich. Eine Reruptur wurde erneut mit Biofix®-Ankern refixiert. Eine weitere Second-look-Arthroskopie 4 Monate p. op. zeigte eine Einheilung.Die Biofix®-Meniskuspfeile sind einfach zu handhaben und bieten eine alternative Methode bei Längsrissen v. a. im Bereich des Hinterhorns in der All-inside-Technik. Posteriore Inzisionen werden vermieden und das Risiko für neurovaskuläre Komplikationen deutlich gesenkt. Die Fehlerrate in stabilen Kniegelenken ist annähernd vergleichbar zu anderen arthroskopischen Techniken. Kritisch zu beurteilen ist die Reizergussbildung, die exakte Längenwahl der Anker, die Schwierigkeit der Versorgung von Rissen im Vorderhorn sowie der Implantatpreis. Speziell bei großen Korbhenkelläsionen empfehlen wir eine Kombination aus Biofix-Ankern und konventionellen Nähten. Insgesamt sind bei den All-inside-Nahttechniken noch einige Verbesserungen der Instrumente und Implantate möglich und zu erwarten.In a current non-comparative study we evaluated the results of the all-inside arthroscopic meniscus repair using the Biofix® meniscus arrows. From Aug 1996 to Oct 1998 45 patients (28 m, 17f; mean age 26 y) had a repair with Biofix® arrows (BIONX Implants Inc.). There were 29 medial and 16 lateral complete vertical peripheral tears more than 1 cm long. 13 of 22 patients with an associated ACL rupture had an ACL repair simultaneously or secondarily. 19 menicsi were repaired 6 weeks or more after injury. In 41 cases only Biofix arrows were used, in 4 patients the arrows were combined with sutures.No neurovascular injury or infection were observed. Twice the arrow slipped off the meniscus and had to be removed intraoperatively. Postoperatively 8 patients had effusions for the first 3 months, additional 4 patients showed irritation at the medial joint line from too long arrows. Twice these arrows were shortened within 6 weeks. 9 patients were symptomatic at latest follow-up and second look arthroscopy revealed a not complete healed meniscus in all cases (4 medial bucket handle, 4 medial posterior horn, 1 lateral bucket handle). Four of these had an unstable knee. The failure rate in stable knees was 14% (5 of 36), respectively. At re-arthroscopy 8 of these 9 patients required a partial meniscectomy, one got a repeat repair with Biofix® arrows. An additional second look arthroscopy due to an effusion showed a healed meniscus.Meniscal tacks or fixators improved the all-inside repair of the meniscus. The Biofix® device is one alternative method to conventional suture techniques with a similar failure rate in stable knees. The principles of meniscus repair like blood supply, synovial rasping, the mechanical axis and a stable knee have to be considered. There has to be some concern about the intraoperative slipping off the meniscus of the arrows, the effusions, the correct choice of the arrow length, the possible cartilage damage due to prominent arrow heads and the costs. We changed our technique to combine the arrows with sutures. Other improvements to avoid some of the mentioned problems may be the the use of headless and cannulated resorbable implants.