[Clinical results after refixation of proximal hamstring tendon ruptures comparing different anchor systems]. / Klinische Ergebnisse nach Refixation proximaler Hamstring-Sehnen-Rupturen unter Berücksichtigung verschiedener Ankersysteme.

BACKGROUND: Injuries to the hamstring muscles and tendon complex are among the most frequent muscular injuries with proximal hamstring tendon avulsion being a particularly severe form. The surgical treatment of these injuries is superior to conservative management with respect to patient satisfaction, recovery of muscle strength and function as well as return to sport rates. It is therefore the method of choice. OBJECTIVE: Presentation and comparison of the surgical results after treatment with titanium, polyether ether ketone (PEEK) and all suture anchors. MATERIAL AND METHODS: A systematic search was carried out in the PubMed medical database and the results are summarized. RESULTS: All systems exhibit comparable biomechanical properties regarding elongation and ultimate failure load. Tendon repair with these anchors results in good to excellent clinical outcomes and shows high return to sport and low complication rates. Patient satisfaction after hamstring tendon repair is reported to be over 90% and return to sport rate is 80-100%. The muscle strength recovers to 80-90% in comparison to the contralateral side. CONCLUSION: All available anchors systems provide good to excellent clinical outcomes and an explicit advantage for one anchor system could so far not be shown.

[Anterolateral stabilization using the modified Lemaire technique for ACL deficiency]. / Anterolaterale Stabilisierung mittels modifizierter Lemaire-Plastik bei insuffizientem vorderem Kreuzband.

OBJECTIVE: Treatment of persistent anterolateral knee instability. INDICATIONS: Subjective/objective (rotational) instability of the knee after anatomic anterior cruciate ligament (ACL) reconstruction. ACL re-rupture including special demands (e.g., high-performance athletes, hyperlaxity) RELATIVE CONTRAINDICATIONS: Osteoarthritis, additional instability of the knee, which should be treated independently; non-anatomic ACL reconstruction with persisting instability should be treated first with anatomic ACL reconstruction. ABSOLUTE CONTRAINDICATIONS: General contraindications for surgery (e. g. septic arthritis), acute irritation of the affected knee. SURGICAL TECHNIQUE: Supine position. Incision along the proximal lateral femoral epicondyle. Marking of the needed width and length of the iliotibial band (ITB) graft. Passing the ITB graft underneath the lateral collateral ligament. Find and mark the isometric point for fixation next to the lateral femoral epicondyle. Fixation of the ITB graft. Layered wound closure. POSTOPERATIVE MANAGEMENT: Knee brace for at least 6 weeks. Range of motion (RoM): from postoperative day 1: flexion-extension 90-0-0°; first 2 weeks after surgery: partial weight bearing (20 kg). RESULTS: An anterolateral extra-articular reconstruction may reduce a persistent anterolateral rotatory instability as well as the re-rupture rate following ACL reconstruction with good patient-reported short-term outcomes. Based on current (biomechanical) data, anterolateral tenodesis seems to be superior to a reconstruction of the anterolateral ligament. If a tenodesis is performed, the graft should be fixed in an isometric position, with neutral rotation of the knee and low graft tension to avoid extraphysiologic load within the lateral compartment. Indications for such a procedure may include a high-grade pivot shift or revision ACL reconstruction as well as a persistent anterolateral rotatory instability following anatomic ACL reconstruction.

[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.

Arthroscopic transtibial pullout repair for posterior meniscus root tears.

OBJECTIVE: Anatomic repair of the torn meniscal root using transosseous sutures through the proximal tibia. INDICATIONS: Nontraumatic meniscal root tears without severe degenerative changes (Kellgren-Lawrence grade ≤ 2), good quality meniscal tissue, traumatic root tears with or without concomitant anterior cruciate ligament tears or multiligament injuries. CONTRAINDICATIONS: Uncorrected varus or valgus malalignment (>3°), osteoarthritis Kellgren-Lawrence grades III and IV, and diffuse articular cartilage changes International Cartilage Regeneration and Joint Preservation Society (ICRS) grades III and IV of the effected compartment, noncompliance. SURGICAL TECHNIQUE: Root tear confirmed by probing; location for the planned root refixation on the tibial plateau is identified. A tibial socket or full transtibial tunnel created with an aiming drill guide. Using a self-retrieving suture passing device or a curved suture passer, the torn meniscus root sutured with no. 0 non-absorbable braided suture. Meniscal sutures passed through the tibial tunnel and the meniscus root reduced into the socket or tunnel by tensioning the free ends of the sutures, followed by fixation on the tibial cortex. FOLLOW-UP: Toe touch weight-bearing for 6 weeks, restricted range of motion (0-60° of flexion) for 6 weeks, no axial loading at flexion angles >90° until 6 months postoperatively. RESULTS: For medial root tears, pullout repair significantly improves functional outcome scores and seems to prevent the progression of osteoarthritis in the short-term. Complete healing observed in only 60% of patients. Negative prognostic factors: varus malalignment > 5°, cartilage degeneration Outerbridge grade III and IV, and older age. Outcomes after lateral root repair are encouraging with apparent prevention of progression of osteoarthritis.

[Fixation of bony avulsions of the posterior cruciate ligament by a suture-bridge™ technique]. / Refixation tibialer knöcherner Avulsionsverletzungen des hinteren Kreuzbandes in Fadenankertechnik.

OBJECTIVE: Anatomical reduction of bony avulsions of the posterior cruciate ligament (PCL) by a suture-bridge™ (Arthrex, Naples, FL, USA) technique to restore posterior knee stability. INDICATIONS: Acute bony tibial avulsions of the PCL and multifragmentary fractures. CONTRAINDICATIONS: Chronic condition of avulsion fractures or posterior instability, advanced knee osteoarthritis, high-grade soft tissue injury, infection. SURGICAL TECHNIQUE: Prone position, minimally invasive posterior medial approach, exposure and reduction of the bony fragment, positioning of the proximal suture-anchor (interfragment), suturing the PCL and knotting to achieve repositioning of the anterior part of the fragment, tighten both ends of the tape by two suture anchors distally to the PCL insertion to fix the posterior part of the fragment. POSTOPERATIVE MANAGEMENT: Knee extension brace with posterior tibial support for 6 weeks, 20 kg partial weight-bearing and restricted flexion up to 90° for 6 weeks, physiotherapy in prone position from the first postoperative day. Full weight bearing after x­ray and clinical control after 6 weeks. RESULTS: Since 2016, 6 cases of a bony avulsion of the PCL treated with this technique (mean age 38 years; range 17-60 years). Postoperative x­ray at 6 weeks showed no fragment dislocation and complete bone healing. Irritation due to the anchor material was not observed up to 6 months postoperatively. No wound healing problems, infections, thrombosis or arthrofibrosis observed. No revisions. According to a recent review comparing the open with an arthroscopic fracture treatment the arthroscopic treatment may lead to a slightly higher subjective and objective outcome. Interestingly, the rate of arthrofibrosis was slightly elevated in the arthroscopic group. Seven of 18 included studies describe a suture fixation in case of a comminuted fracture. Especially in these cases a suture-bridge ™ fixation seems to be reasonable.

[Distal femoral osteotomy using a lateral opening wedge technique]. / Distale Femurosteotomie in lateraler Open-wedge-Technik.

OBJECTIVE: To shift the weight-bearing axis of the lower limb medially by opening a lateral-based metaphyseal osteotomy at the distal femur. INDICATIONS: Femoral-based valgus malalignment and symptomatic lateral unicompartimental osteoarthritis, lateral hyperpression syndrome, cartilage therapy of the lateral compartment, lateral meniscal replacement/transplantation, medial instability with valgus thrust, reconstruction of the medial collateral ligament, patellar instability and/or maltracking. CONTRAINDICATIONS: Advanced cartilage damage (>grade 2) or subtotal meniscal loss of the medial compartment, age >65 years (relative), nicotine abuse, body mass index >30, flexion contracture >25°, corrections with a wedge base >10 mm in case of congenital deformities, inflammatory or septic arthritis, severe osteoporosis. SURGICAL TECHNIQUE: Lateral approach to the distal femur; biplanar osteotomy (frontal + axial osteotomy), gradual opening of the osteotomy, osteotomy fixation with a locking plate. POSTOPERATIVE MANAGEMENT: Free range of motion. Partial weight bearing with 20 kg for 2 weeks, followed by progressive weight bearing thereafter. RESULTS: Mean improvement of knee scores from 20-30 points and mean 10-year survival rate of 80% in patients with lateral unicompartimental osteoarthritis. Mean complication rate of 9%.

[Patellofemoral arthroplasty]. / Der femoropatellare Teilersatz.

OBJECTIVE: Isolated resurfacing of the trochlea using an inlay prosthesis without changing the complex kinematics of the patellofemoral joint. INDICATIONS: Symptomatic, isolated patellofemoral osteoarthritis or isolated osteochondral lesions, failed conservative and cartilage regeneration procedures. No or concurrently corrected ligament instability, tibiofemoral and patellofemoral malalignment. CONTRAINDICATIONS: Symptomatic patellofemoral osteoarthritis, inflammatory joint disease, chondrocalcinosis, chronic pain syndromes, active infections or knee ankylosis. SURGICAL TECHNIQUE: Following a medial arthrotomy, coronal and sagittal curvatures of the trochlea are measured. Based on these measurements, corresponding surface reamers create an implant bed by removing damaged cartilage of the trochlea. A central fixation screw is placed to the desired depth and the inlay prosthesis is tapped carefully onto it. Final placement of the prosthesis is targeted slightly recessed to the surrounding joint surface. POSTOPERATIVE MANAGEMENT: Free passive range of motion exercises of the knee joint are recommended starting on postoperative day 1. Depending on symptoms (e.g., pain and joint effusion), partial weight-bearing of 20 kg is allowed during postoperative weeks 1 and 2, which is increased by 20 kg/week thereafter. RESULTS: In a prospective study of 29 patients (mean age: 42 years) treated with inlay arthroplasty, 2­year follow-up results showed significant improvements (p < 0.05) in WOMAC, IKDC and VAS (pain) scores when compared to baseline. Compared to onlay PF arthroplasty modern inlay prosthetic placement showed a better preservation of the tibiofemoral joint without progression of tibiofemoral degeneration. This may be due to possible avoidance of patellofemoral overstuffing using a more physiological placement of the inlay prosthesis.

Surgical treatment of acute acromioclavicular joint dislocations: hook plate versus minimally invasive reconstruction.

PURPOSE: This study was performed to compare the clinical results of a minimally invasive technique for acute acromioclavicular (AC) joint dislocation repair with the traditional hook plate fixation. METHODS: Forty-four patients with an acute (within 2 weeks after trauma) complete AC joint separation (35 male, nine female; median age 36.2 years, range 18-56) underwent surgical repair with either a minimally invasive AC joint repair or a conventional hook plate. Functional outcome was evaluated using the Constant-Murley Score (CMS), the TAFT score and the AC joint instability score (ACJI). Radiographic evaluation was performed with bilateral anterior-posterior (a.p.) stress and Alexander views. RESULTS: All patients were available after a median follow-up of 32 months (range 24-51). There were no significant differences in the mean CMS, Taft score and the ACJI between the two groups. The radiological assessment revealed no significant difference in the coracoclavicular distance. In both groups, a slight loss of reduction was observed. Periarticular ossification was seen in 11 patients of the minimally invasive AC joint repair and eight patients of the hook plate group but this did not affect the final outcome. Hook plates were removed after a median interval of 11.9 weeks (range 10-13). CONCLUSION: Good clinical results can be achieved with both minimally invasive AC joint repair and hook plate fixation. However, in the hook plate group a second operation is mandatory for plate removal. LEVEL OF EVIDENCE: III.

[Suturing and refixation of the medial collateral ligament in severe acute medial instability of the knee]. / Naht und Refixation des medialen Kollateralbandkomplexes bei schwerer akuter medialer Instabilität des Kniegelenks.

OBJECTIVE: Restoration of the medial stability after acute lesion of the medial collateral ligament (MCL) and of the posteromedial complex in case of a high grade instability of the MCL. Stabilization against valgus stress and prevention of an increased posterior drawer in case of a lesion of the posterior oblique ligament (POL). INDICATIONS: Acute high grade instability (grade 3) of the MCL. Rupture of the POL in combination with a rupture of the PCL and/or of the ACL. Multiligamentous injuries. Stener-like lesion of the tibial insertion of the MCL fibers with subluxation of the MCL superficial to the pes anserinus superficialis. CONTRAINDICATIONS: Local infection, poor soft tissue condition, severe soft tissue defects, intraligamentous injuries of the MCL (grade I-II instabilities). SURGICAL TECHNIQUE: The refixation of the MCL and the posteromedial complex has to respect anatomical situation. Femoral or tibial avulsions of the MCL can be reattached by the use of anchors at the anatomical insertion sites. Intraligamentous ruptures must be adapted. Additional framelike sutures may be used. The fixation and readaption of the MCL and the posteromedial complex can be combined with ACL and PCL procedures. POSTOPERATIVE MANAGEMENT: Use of a brace for 6 weeks to avoid valgus stress, partial weight bearing (10-20 kg). Weeks 1-3: ROM 0-20-60° extension/flexion; weeks 4-6: ROM 0-10-90° extension/flexion; after 7 weeks: free ROM. The postoperative protocol must be more restrictive in case of a combination of a MCL fixation and a PCL reconstruction (6 weeks immobilization in extension with posterior support, exercise only in prone position). RESULTS: Between 2010 and 2013, 34 cases of acute medial instability were treated. According to the injury pattern, some procedures were isolated MCL refixations, while others were combined procedures. While 25 patients showed a concomitant ACL injury, 13 patients had combined PCL and ACL injury. Postoperatively all medial instabilities had improved. Revision surgery was performed in 3 cases due to postoperative arthrofibrosis.

[Anatomic reconstruction of the anterior cruciate ligament with the autologous quadriceps tendon. Primary and revision surgery]. / Anatomische Ersatzplastik des vorderen Kreuzbandes mit der autologen Quadrizepssehne. Primär- und Revisionsoperation.

OBJECTIVE: Restore function of the anterior cruciate ligament (ACL). INDICATIONS: Chronic functional instability with rupture of the ACL, giving way phenomena, acute rupture of the ACL with concomitant meniscus repair, rerupture of ACL graft with anatomical tunnels. CONTRAINDICATIONS: Local infection of the skin at the knee joint, local soft tissue damage, after rupture of the quadriceps tendon, enthesopathia of the quadriceps tendon, lack of patient compliance. SURGICAL TECHNIQUE: Harvest quadriceps tendon graft with a bone block via a 4-5 cm long incision, starting from the middle third of the proximal patella pole without damaging the tendon fibers. Drill the femoral tunnel via a deep anteromedial portal with the knee flexed of more than 110° (tunnel diameter 0.5-1 mm smaller in diameter than bone block). Gentle tunnel preparation using dilators. In absence of an ACL stump the lateral meniscus anterior horn serves as tibial landmark. In case of revision surgery, remove graft material and implants from the tunnel. Graft fixation using press fit method in the femoral tunnel. Tibial graft fixation archieved with a resorbable interference screw and a button. POSTOPERATIVE MANAGEMENT: Goal of the inflammatory phase (weeks 1-2) is pain and inflammation control (20 kg partial weight bearing). During the proliferative phase (weeks 2-6), load and mobility slowly increased (closed-chain exercises). During the remodeling phase (> 6 weeks), strength and coordination exercises are performed. In revision cases and in case of concomitant injuries, longer partial weight-bearing period might be necessary. Athletes should not return to competitive sports before 6-8 months. RESULTS: In a prospective study, 33 patients (age 16-48 years) were examined after replacement of the ACL with a quadriceps tendon graft after a minimum follow-up (FU) of 2 years (12 revision; 21 primary surgery). No post- or perioperative complications. Postoperative radiographs showed an anatomical tunnel location and no dislocation of the bone block. After 2 years the difference of a-p translation compared to the other leg was assessed by the use of KT 1000. The revision group improved from an average of 7.2 mm (pre-op) to 2.2 mm (FU). The group with primary surgery improved from 6.4 mm (pre-op) to 1.7 mm (FU). A sliding pivot shift phenomenon was detected in 2 patients in the revision group and 1 patient in the primary surgery group.

[Medial closing wedge osteotomy for correction of genu valgum and torsional malalignment]. / Osteotomie am distalen Femur zur Korrektur von Genu valgum und Torsionsfehlern.

OBJECTIVE: Femoral medial closing wedge osteotomy for the correction of valgus malalignment to unload the cartilage in the lateral compartment and/or correction of symptomatic torsional malalignment. INDICATIONS: Lateral unicompartmental osteoarthritis of the knee with genu valgum in young patients. Symptomatic torsional malalignement of > 30° and < 0°. CONTRAINDICATIONS: Grade 3 and 4 cartilage damage in the medial compartment. Heavy smoking. Medial meniscectomy. Extreme obesity. Inadequate soft tissue conditions. SURGICAL TECHNIQUE: The operation begins with arthroscopy of the knee joint. In case of grade 4 lateral cartilage damage, a microfracture is performed. The distal femur is exposed via an anteromedial longitudinal incision starting 10 cm above the patella and ending in the upper third of the patella. The medial femoral cortex is exposed using Hohmann retractors and an oblique closing wedge osteotomy is performed with an oscillating saw. In case of valgus correction, the lateral cortex is left intact. In case of correction of torsional malalignment, the osteotomy plane is horizontal and the lateral cortex is cut. The wedge height is determined preoperatively based on full leg x-rays. The leg axis is controlled intraoperatively with a long metal rod and the use of an image intensifier. The osteotomy is manually closed and stabilized with a locking plate. POSTOPERATIVE MANAGEMENT: The patient is mobilized under load with 20 kg body weight for the first 6 postoperative weeks. Full range of motion is permitted. RESULTS: We treated 23 patients with lateral cartilage damage (grades 3 and 4) and genu valgum with medial closing osteotomy of the distal femur (6 men and 17 women). After 3.5-years follow-up, the KOOS increased from 48.4 points to 84.9 points. In one case, there was an early loss of correction, with subsequent revision with bone grafting and lateral osteosynthesis. No peri-or postoperative complications such as infection, thrombosis, and embolism occurred. In 5 cases a torsional osteotomy was performed. The torsional osteotomy was performed 4 times due to chronic patellofemoral instability, and once due to a medial tibiofemoral instability. Healing complications were not observed in this population. Recurrent instability was not observed.

[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.