[Diagnosis and therapy of chronic patellofemoral instability]. / Diagnostik und Therapie der chronischen patellofemoralen Instabilität.

The chronic patellofemoral instability is a multifactorial disease, which is mostly congenital. Luxation of the patella is mainly atraumatic. Sole conservative treatment is often unsuccessful. Surgical treatment is needed in most cases and requires consideration of all pathologic changes of the patella-stabilizing anatomic structures. Rupture of the medial patellofemoral ligament is almost pathognomonic. In addition, the frontal mechanical axis, rotation of femur and tibia, the trochlear shape, the distance from the tibial tuberosity to the trochlear sulcus and the patellar height play an important role. Often, in addition to soft tissue reconstruction, the bony alignment needs to be corrected. Consideration of risk factors in both adult and adolescent patients is needed to avoid recurrent instability.

[Patellar tendon ruptures : Internal bracing and augmentation technique]. / Patellarsehnenruptur : Internal Bracing und Augmentationstechnik.

OBJECTIVE: To report a surgical technique for the treatment of patellar tendon ruptures augmented with an internal brace suture tape. INDICATIONS: Acute patellar tendon ruptures, fractures of the distal patellar pole, chronic insufficiency of the patellar tendon or revision surgery for failed repairs. CONTRAINDICATIONS: Severe damage to the surrounding soft tissue. Local infection. Life-threatening conditions. SURGICAL TECHNIQUE: Direct longitudinal anterior approach to the patellar tendon. Two parallel transosseous bone tunnels are drilled in the patella and tibial tuberosity with a 2.4 mm drill bit. Two separate FiberTapes® (Arthrex, Naples, FL; USA) are shuttled through the proximal and distal bone tunnels around the tendon in "X" and "O" type configuration. Patellar height is reestablished under fluoroscopic control and both FiberTapes are tied down. Both tendon ends are debrided and readapted with absorbable sutures. POSTOPERATIVE MANAGEMENT: Passive motion exercise to 90° of flexion from day 1. Partial load to 20 kg of body weight with knee in locked full extension brace during first 2 weeks. Isometric exercises from week 3. Passive flexion to 110° from week 4 (adapted to pain). Free active range of motion and weight bearing from week 7. RESULTS: In more than 10 years of clinical application, positive results were continuously found in acute as well as chronic patellar tendon ruptures. These results are consistent with those in the current literature.

[Acute injury of the posterior cruciate ligament with femoral avulsion : Arthroscopic ligament repair and bracing]. / Akute Verletzung des hinteren Kreuzbandes mit femoraler Avulsion : Banderhaltende arthroskopische Refixation und Bracing.

OBJECTIVE: The aim of arthroscopic bracing of the posterior cruciate ligament (PCL) is to restore anatomic and biomechanic function in acute PCL tears. Therefore, primary augmentation of the PCL by using a stable suturing system is used. INDICATIONS: Acute tears of the PCL, femoral avulsions, isolated or combined in cases of multiligament injuries (knee dislocations of Schenk types II-IV). CONTRAINDICATIONS: Chronic instabilities of the PCL, infection of the knee joint. SURGICAL TECHNIQUE: Arthroscopic preparation of the femoral PCL footprint. Suturing of the PCL stump with non-resorbable sutures. Placement of the femoral and tibial tunnel with a specific arthroscopic PCL guide. Femoral fixation of the bracing system and the PCL augmenting sutures extracortical via a button or intraarticular with a suture anchor. Tibial fixation via a button has to be performed in a minimum of 80° of flexion and under permanent anterior drawer tension. POSTOPERATIVE MANAGEMENT: Brace in full extension with posterior support 24 h/day, range of motion (ROM) restricted up to 90° of flexion and limited weight bearing with 20 kg for the first 6 weeks postoperatively. After 6 weeks, weight bearing and ROM can be increased and a solid frame brace with posterior support is recommended for the next 6 weeks.

[Patellar sleeve fractures : Bracing and augmentation technique with suture tape]. / Patella-Sleeve-Fraktur : Bracing- und Augmentationstechnik mit einem Fadentape.

OBJECTIVE: Transosseous augmentation of patellar sleeve fractures (PSF) with suture tape in young athletes. INDICATIONS: Acute avulsions of the proximal or distal patellar pol with clinical relevant deficit of knee extension. CONTRAINDICATIONS: Local infections, severe soft tissue damage (relative contraindication), fractures of the patella or tibial tuberosity. SURGICAL TECHNIQUE: Direct longitudinal anterior approach to the patella. Debridement of the proximal patellar tendon insertion. Anatomic reduction of any osteochondral fragments. Transosseous augmentation of the tendon with FiberTapes® (Arthrex, Naples, FL, USA). POSTOPERATIVE MANAGEMENT: Passive motion exercise to 30° of flexion from day 1; increase to 60° from week 3; 90° from week 5. Partial load-bearing of 20 kg with knee in locked full extension brace during first 2 weeks. Isometric exercises from week 3. Free active ROM and full weight bearing from week 7. RESULTS: If diagnosis and treatment is early and sufficient augmentation of the tendon and periosteum is provided, good to excellent functional outcome can be expected.

[Arthroscopic refixation of acute proximal anterior cruciate ligament rupture using suture anchors]. / Arthroskopische Refixation einer akuten proximalen vorderen Kreuzbandruptur mittels knotenlosem Fadenanker.

OBJECTIVE: Arthroscopic assisted suture anchor refixation combined with microfracturing of the femoral ACL insertion zone in cases of acute proximal anterior cruciate ligament (ACL) rupture to restore anatomical and biomechanical properties of the native ACL. INDICATIONS: Acute proximal ACL rupture/avulsion, multiligament injury of the knee CONTRAINDICATIONS: Chronic (>6 weeks) proximal ACL rupture, intraligamentary rupture, as well as previous ACL surgery. SURGICAL TECHNIQUE: Arthroscopic examination of the knee joint, debridement of the femoral insertion zone, examination of the ligament quality by a probe, insertion of a curved lasso through the ACL to place the sutures and use of a drill guide to place the anchor in the middle of the femoral ACL insertion. Microfracturing holes around the femoral footprint were made by an awl to enhance healing properties of the ACL. POSTOPERATIVE MANAGEMENT: Partial weight bearing was permitted and crutches were used for 6 weeks, knee brace limited for the first 2 weeks 0­0-0°, then 0­0-90° for the following 4 weeks. RESULTS: A total of 20 patients who underwent acute proximal ACL suture anchor refixation were evaluated after a mean follow-up of 28 months. Regarding stability, mean values of the KT-1000 arthrometer indicated stable results (<3 mm), 3 patients had a 1+ Lachman and 4 patients had a 1+ pivot shift. IKDC (International Knee Documentation Committee) score indicated that 17 cases were very good to good (12A, 4B) and in 3 cases the results were satisfactory (3C). Magnetic resonance imaging showed that the ALC was found to be intact in 17 cases. The total rate of revision was 15 % (3/20) because of recurrent instability.

[Unicompartimental joint (Oxford III) with mobile bearing : Minimally invasive implantation of a in the medial compartiment]. / Unikompartimentelle Oxford-III-Prothese mit mobilem Gleitlager : Minimal-invasive Implantation im medialen Kniegelenkskompartiment.

OBJECTIVE: Replacement of the joint surfaces in the medial compartment by an endoprothesis with a mobile bearing. INDICATIONS: Unicompartimental anteromedial gonarthrosis with an intact anterior cruciate ligament. Avascular necrosis at the medial femoral condyle. CONTRAINDICATIONS: Third to fourth degree cartilage damage in the lateral compartment. Lateral menisectomy. Symptomatic osteoarthritis in the femoropatellar joint. Chronic polyarthritis. More than 15° varus. Varus passive not redressable. Medial or lateral subluxation. More than 15° extension deficit. Passive flexion less than 110°. Cruciate ligament lesions with instability. Poor soft tissue conditions. SURGICAL TECHNIQUE: The leg is mounted on an electric leg holder that allows flexion up to 120°. The joint is opened via an anteromedial arthrotomy starting at the medial border of the patella and ending 3 cm below the tibia plateau. The osteophytes are resected and the tibial resection is performed with an oscillating saw under guidance of a jig which is positioned according to the physiological tibial slope. The medial collateral ligament must be protected with a Hohmann retractor. The vertical cut is performed first; then the horizontal cut is performed. The size of the resected plateau should allow space for a tibial component and a meniscus implant of 4 mm. The resected plateau seves to determine the size of the plateau. The jig for the femoral preparation is adjusted according to the axis of femur and tibia. After the posterior resection the 0 mm spigot is inserted into the central drill hole and the distal part of the condyle is milled. The depth of milling is determined by equalizing the flexion and extension gap. Extension and flexion gap balancing is controlled with test inlays. Posterior osteophytes at the medial femur condyle are cut with a special chisel. In the anterior aspect bone resection is needed to prevent impingement of the meniscus implant. Then the tibia plateau is finally prepared. After inserting the test implants the femoral and tibial components are cemented in one or two stages. POSTOPERATIVE MANAGEMENT: The patient is mobilised under full weight bearing with two crutches. RESULTS: A total of 50 Oxford III hemiarthroplasties were implanted using the minimal invasive technique. Indication was an anteromedial gonarthrosis with intakt anterior cruciate ligament. Age varied between 59 and 79 years with a mean of 71 years. Follow-up was 5 years. There were three revisions till final follow-up. Cause was an inlay luxation in one case and in two cases with lateral arthrosis. The average KOOS score was 92.3 points (± 6 points).

[Anatomic reconstruction of the anterior cruciate ligament in single bundle technique]. / Die anatomische Ersatzplastik des vorderen Kreuzbands in Einzelbündeltechnik.

OBJECTIVE: Restore the knee stability by ACL reconstruction of the anterior cruciate ligament. INDICATION: Acute and chronic functional instability with rupture of the anterior cruciate ligament giving way phenomena, acute rupture of the anterior cruciate ligament with concomitant meniscus repair. CONTRAINDICATIONS: Local infection in the knee joint, local soft tissue damage, lack of cooperation of the patient. SURGICAL TECHNIQUE: The operation begins with the examination under anesthesia. It follows an arthroscopic examination of the knee and the arthroscopic treatment of accompanying intra-articular lesions (meniscus and cartilage damage). The semitendinosus tendon is harvested via a 3 cm skin incision medial to the tibial tuberosity. A four stranded tendon graft is prepared with a minimum length of 6.5 cm. Alternative grafts for this technique are the patellar tendon, quadriceps tendon, and allografts. The femoral tunnel for the ACL graft is drilled via a deep anteromedial portal under arthroscopic control. For precise placement of the guide wire a specific offset aimer is used. For drilling the knee must be flexed more than 110°. Landmarks are the intercondylar line and the cartilage-bone interface. The position of the guide wire is always controlled by the medial portal (medial portal view). The guide wire is overdrilled with a cannulated drill (4.5 mm when a flip tack is used). The drill diameter for the 30 mm long blind tunnel is chosen according to the graft diameter. A gentle tunnel preparation may be achieved with the use of dilators. At the tibia, the anterior horn of the lateral meniscus is used as a landmark in the absence of ACL stump. The guide wire is first overdrilled with a 6 mm drill. Slight adjustments to the tibial tunnel location can be archieved when the guide wire is overdrilled eccentrically with a larger drill. At the femur an extracortical fixation technique with a flip button is preferred. At the tibia, a hybrid fixation with absorbable interference screw and button is used. REHABILITATION: The rehabilitation program is divided into three phases. During the inflammatory phase (1st-2nd week) control of pain and swelling is recommended. The patient is immobilized with 20 kg partial weight bearing. During the proliferative phase (3 nd-6th week), load and mobility are slowly increased. Goal of this phase is it full extension. Exercises should be performed in a closed chain. During the remodeling phase strength and coordination exercises can be started. Athletes should not return to competitive sports before the 6th to 8th month. RESULTS: In a prospective study, we have examined 21 patients treated with an anatomic anterior cruciate ligament reconstruction in single-bundle technique, after two years. As graft the semitendinosus was used. The postoperative MRI diagnosis showed that all tunnels were positioned anatomically. KT 1000 measurement showed that the difference of anterior translation decreased from an average of 6.4-1.7 mm. A sliding pivot shift phenomenon was detected in only one patient. The postoperative Lysholmscore was 94.2 points.

[Arthroscopic arthrolysis of the elbow joint]. / Die arthroskopische Arthrolyse des Ellenbogengelenks.

OBJECTIVE: Arthroscopic assisted improvement of range of motion in elbow stiffness. Detailed diagnostic evaluation including medical history and preoperative radiographs, CT and MRI scans are necessary for planning the operative treatment. INDICATIONS: Restricted range of motion < 30° in extension and/or more than 100° in flexion related to intraarticular causes (loose bodies, osteophytes or contracture of the capsule). CONTRAINDICATIONS: Extension deficit > 30°, extraarticular causes (e.g., heterotopic ossifications), nerve irritation, incongruity of joint surfaces, acute joint infection. SURGICAL TECHNIQUE: Prone position, filling of the joint with irrigation fluid, arthroscopic examination of the anterior and posterior compartment. Partial synovectomy, debridement and capsular release, removal of loose bodies and resection of osteophytes. POSTOPERATIVE MANAGEMENT: Intensive physiotherapy, continuous passive motion. Plexus anesthesia and nonsteroidal antiphlogistic medication. RESULTS: A total of 29 patients who underwent arthroscopic arthrolysis of the elbow joint were evaluated after a mean follow up of 15.4 months after surgery. Average preoperative extension deficit improved from 23° to 5°. Mean preoperative flexion improved from 115° to 131°. Improvement of range of motion was 34° on average. No vascular or neurologic complications were noted. Infection was not observed. In one case, stiffness persisted and early arthroscopic revision was needed. Postoperative patient satisfaction on the VAS Scale was 8.9. The Mayo Elbow Performance Index was 92.9 points on average.

[Chronic patellofemoral instability]. / Chronische patellofemorale Instabilität.

Chronic patellofemoral instability may lead to pain and early osteoarthrosis. Recurrent dislocations of the patella, lateral subluxation and chronic dislocation are summarized under this generic term. There are five different factors which may be responsible of the development of chronic patellofemoral instability: 1) elongation of the medial patellofemoral ligament (MPFL), 2) patella alta, 3) increased distance between tibial tuberosity and trochlea groove (TTTG) distance, 4) trochlea dysplasia and 5) torsional malalignment. To rule out these factors clinical examination, radiological diagnostics (luxation, subluxation in the Defilée view, trochlea morphology, patella alta) and magnetic resonance imaging (MRI) of TTTG distance and trochlea morphology are crucial. The indications of operative treatment are chronic pain with subluxation, chronic dislocation and recurrent dislocation. Currently the former frequently and universally used lateral release is only indicated in cases of subluxation and positive tilt. Biomechanical studies have shown that a lateral release will otherwise increase patellofemoral instability. The choice of the surgical technique depends on the factors underlying patellofemoral instability, the conditions of growth plate and cartilage damage. Among the different surgical options proximal and distal realignment procedures are differentiated. In cases of MPFL elongation and mild passive instability a medial reefing might be successful. In cases of MPFL elongation, high passive instability up to 30° of flexion (with or without trochlear dysplasia) MPFL reconstruction may be the treatment of choice. A trochleoplasty is rarely indicated. This treatment may be considered in cases of high grade trochlea dysplasia and passive instability at more than 30° of flexion. If the TTTG distance is increased (>20 mm) or in cases of patella alta distal realignment with tibial tubercle transfer should be considered. This operation might also be useful in the presence of lateral cartilage damage as an anteromedialization of the patella.