[History of implant-free anterior cruciate ligament reconstruction]. / Geschichte des implantatfreien Kreuzbandersatzes.

Most recent articles on anterior cruciate ligament (ACL) reconstruction focus on anatomic tunnel placement, but reviewing the early history of ACL reconstruction it can be seen that at the beginning of the 20th century Ernest Hey-Groves had already pointed out the importance of anatomic placement of the tunnels. Palmer even developed a femoral drill guide for precise anatomic placing of the tunnel before World War II. The possibility of graft fixation without any fixation material is also not new and was described as early as 1967 by Brückner from Rostock. Many techniques in ACL reconstruction with non-anatomic placement and high failure rates could have been avoided if surgeons had been aware of what the early pioneers in this important field of orthopedic surgery had already described.

[Anatomic anterior cruciate ligament reconstruction with hamstrings using press-fit fixation without hardware: operative technique and long-term results of a prospective and randomized study]. / Anatomische vordere Kreuzbandersatzoperation mittels Semitendinosus- und Grazilissehne in fremdmaterialfreier Press-fit-Technik: Operative Technik und Langzeitergebnisse einer prospektiven und randomisierten Studie.

An innovative technique for anterior cruciate ligament (ACL) reconstruction has been developed in 1998 which allows the grafts to be fixed by press-fit to the femoral and tibial tunnel without any hardware. The semitendinosus (ST) and gracilis tendons (GT) are built into a sling by tying a knot with the tendon ends and securing the knot after conditioning by sutures. For the femoral tunnel the anteromedial porta is used. The correct anatomic position of the single femoral tunnel is checked using intraoperative lateral fluoroscopy by placing the tip of a K-wire to a point between the anteromedial and posterolateral bundle insertion sites. A femoral bottleneck tunnel is drilled to receive the knot of the tendons. The tendon loops filled the tibial tunnel without any suture material. The loops are fixed at the tibial tunnel outlet with tapes over a bone bridge. Between 1998 and 1999 a prospective randomized study (level 1) was conducted comparing this technique with a technique using bone-patellar-tendon graft and press-fit fixation without hardware. In conclusion it was found that implant-free press-fit ACL reconstruction using bone-patella-tendon (BPT) and hamstring tendon (HT) grafts proved to be an excellent procedure to restore stability and function of the knee. Using hamstring tendons (ST and GT) significantly lower donor site morbidity was noted. Kneeling and knee walking pain persisted to be significantly more intense in the BPT up to 9 years after the operation. Re-rupture rates, subjective findings, knee stability and isokinetic testing showed similar results for both grafts. This is the first level I study which demonstrates cartilage protection by ACL reconstruction as long as the meniscus is intact at index surgery, shown by bilateral MRI analysis 9 years post-operation. There was no significant difference in the average grade of chondral and meniscus lesions between BPT and HT and in comparison of the operated to the intact knee, except for grade 3-4 lesions found at the 9 year follow-up, which were significantly higher in the BPT group.

[Arthroscopic treatment of chronic tendinosis of the patellar tendon (Jumper's Knee): surgical technique]. / Die arthroskopische Behandlung der chronischen Tendinose der Patellarsehne (Jumper's Knee): Operationstechnik.

The described surgical technique with the arthroscopic resection of the lower patellar pole for the treatment of chronic patellar tendinosis leads to excellent clinical results. It combines the advantages of a minimal-invasive method with fast rehabilitation and return to sporting activities with comparable results to described open procedures.

[Jumper's knee--a review]. / Jumper's knee -- eine Ubersicht.

Jumper's knee has been defined as painful chronic overuse injury of the extensor mechanism of the knee joint. The disease has a high incidence in jumping sports and depends on training frequency and level of performance. Its natural course is protracted, repetitive, and often bilaterally occurring. Its etiology is a chronic overload of the knee extensor mechanism which is triggered by jumping sports (volleyball, basketball etc.) as well as different intrinsic (ligamentous laxity, Q-angle, patella height, tenderness, pattern of force development) and extrinsic dispositions (frequency of training, level of performance, hardness of underground). The place of pathology most often is the osteo-tendinous transition zone of the proximal patellar tendon. Histologic evaluation of the tendon showed that the disease is rather degenerative than inflammatory. The diagnosis is primarily based on the typical sports history, physical examination, and ultrasound. MRI is helpful in operation planning. Plain radiography, CT, and bone scans are used to rule out differential diagnoses. Therapy should be chosen according to the stage of the disease and usually starts with a non-surgical approach. This includes rest from sports activities, immobilisation, non-steroid antiphlogistics, para-tendinous cortisone injections, massage, electric therapy, ultrasound and extracorporal shock waves. Afterwards an increase of activities is begun (moderate training, adequate warm-up, ice cooling after activity, muscle stretching, eccentric strengthening of the quadriceps). Patella straps and soft insoles are used as prevention. Up to 42 % of patients need surgical therapy after failure of long-lasting non-surgical measures, carried out either open or arthroscopically. Surgical principles include excision of the para-tendon, excision of the degenerative tissue, resection of the lower patella pole, and longitudinal incisions into the tendon. Most patients are pain-free after surgery but return to sports only at a lower level.

[MRI evaluation of meniscal movement and deformation in vivo under load bearing condition]. / Kernspintomographische Untersuchung der Meniskusbeweglichkeit und -deformation in vivo unter Gewichtsbelastung.

AIM: The aim of this experimental study was a quantitative evaluation of meniscal movement and deformation in vivo under load bearing conditions. METHODS: Sagittal T1-weighted MRI pictures of 15 healty knees were evaluated. The subjects were placed in an open MRI, that enabled measurements under load bearing and in different flexion grades. Series of pictures of the medial and lateral meniscus without load, with half and full body weight load and in full extension and 30 degrees flexion were taken. Two examiners measured twice the height of the posterior horn, and the inner and outer distance between the anterior and posterior horns of the menisci. RESULTS: The height of the posterior horns of the medial and lateral menisci decreased with increasing load. The inner and outer distance increased with load, the inner distance more than the outer, resulting in a compression of the periphery. Increase of flexion from 0 degrees to 30 degrees significantly influenced only the outer distance of both menisci. CONCLUSION: This method can be used in future to functionally evaluate the postoperative result after meniscus saving or replacing therapies. The compression of meniscal periphery from the inside to the outside under load in full extension allows early postoperative mobilisation after meniscal sutures.

[Intraoperative quality control of the placement of bone tunnels for the anterior cruciate ligament]. / Intraoperative Qualitätskontrolle bei der Bohrkanalplatzierung zum vorderen Kreuzbandersatz.

The reconstruction of a ruptured anterior cruciate ligament (ACL) is a frequently performed operation, however technically demanding with a revision rate of approximately 10%. The correct placement of bone tunnels in femur and tibia is the most important variable to achieve a successful outcome. A distinct knowledge of the anatomic insertion sites is crucial. The ideal location for the femoral bone tunnel is achieved when a 1-2 mm posterior wall is left to the over-the-top position and when the entry to the bone tunnel is at 10 o'clock (right knees) or 14 o'clock (left knees) in the frontal plane. The femoral bone tunnel can be drilled through the tibial bone tunnel (transtibial technique) or through an anteromedial arthroscopic portal. According to recent studies the use of an anteromedial portal helps to reduce the risk of misplacement of the bone tunnel. The center of the tibial bone tunnel should be located on an imaginary line between medial border of the anterior horn of the lateral meniscus and the medial tibial spine. The position of the tibial guide wire has to be far enough posterior to avoid impingement of the graft with the roof of the intercondylar notch. Measures for quality control include the intraoperative use of an image intensifier (fluoroscopy), instrumented laxity measurements and a postoperative radiograph in 2 planes. The use of computer assisted surgery cannot routinely be recommended at present.

[Internal rotational strength of the thigh after ACL reconstruction. Prospective comparison of harvesting of the semitendinosus and gracilis tendons and the patella tendon]. / Innenrotationskraft des Unterschenkels nach Kreuzbandrekonstruktion. Prospektiver Vergleich zwischen Entnahme der Semitendinosus- und Grazilissehnen und der Patellasehne.

AIM: The aim of the present study was the prospective, randomized evaluation of the internal rotation strength in patients, undergoing ACL reconstruction using either semitendinosus and gracilis tendon autografts (ST/G) or the central third of the patella tendon (BPT). METHOD: 40 patients (20 male, 20 female, average age 32 years [16 - 49]) underwent reconstruction of the ACL. In 20 patients ST/G was used, in 20 matched patients the central third of the patella tendon (BPT) was used. Rehabilitation was identical for both groups. The isometric strength of internal tibial rotation in neutral position was measured preoperatively, 3, 6 and 12 months postoperatively. RESULTS: After 3 months no difference to the preoperative data was found. After six months the internal tibial torque was significantly higher (p < 0.05) than preoperatively. No additional increase was found after 12 months. There was no statistically significant difference between both groups at any time. CONCLUSION: The internal tibial torque, which is predominantly a function of the pes anserinus, recovers shortly after operation and is, due to postoperative rehabilitation, significantly elevated after 6 months. The randomized comparison with the harvesting of the central third of the patellar tendon showed no significant difference.

[Effects of knee braces on sensorimotor capabilities of patients with ACL reconstruction]. / Auswirkungen einer Knieorthese auf die sensomotorischen Fähigkeiten bei Patienten mit einer VKB-Plastik.

In 25 test persons with Anterior-Cruciate-Ligament (ACL)-Operation the sensomotory capabilities of the affected and the unaffected side were examined by KAT 2000 (BREG Inc., Vista, C.A., USA) with and without knee-brace (Hypex knee-brace/Fa. Aircast-Europa GmbH). The results were compared with those of a control group. In all cases of test variations (both leg-static/both leg-dynamic/one leg-static) there were significant differences between testing with and without knee brace. In the one leg-static test there was an improvement of 30% (p < 0.01), in the both leg-static test an improvement of 24% (p < 0.01). The both leg-dynamic showed a similar result (23.8%; p < 0.01). These noticed adaptations may be mediated by improvements of proprioceptive and exteroceptive capabilities and a positive impact on the anticipative control of behavior. The results of the control group differ in only a few cases from the results in the group of patients. This may be judged as indicator for the variety of sensomotory capabilities in the general population.

Computed tomography-guided endoscopic removal of an osteoid osteoma from the femur.

The case of a 19-year-old male patient who complained of dull pain in his right knee for more than 18 months and was finally diagnosed with intracortical osteoid osteoma in the femoral diaphysis is presented. A new operative method was used to locate and remove the tumor. Under spinal anesthesia with the patient in the prone position, a lateral and a posterior approach were marked with special bone cutting tubes under computed tomographic control. The usual arthroscopic instruments (punch, retrograde suction stamp) were used to remove the nidus under arthroscopic visualization, thereby avoiding the disadvantages of open excisions, such as large incisions, bone loss, long hospitalization, and risk of infection. The advantages and disadvantages are thoroughly discussed and compared with conventional surgical procedures.

[Microfracture for treatment of cartilage detects]. / Die Mikrofrakturierung zur Behandlung von Knorpeldefekten.

Subchondral bone plate microfracture technique (Steadman) has shown to enhance chondral resurfacing by providing a suitable environment for tissue regeneration and taking advantage of the body's own healing potential. Microfracture technique belongs to the bone marrow stimulating methods like abrasion arthroplasty or subchondral bone drilling. Using a specially designed awl or pick, multiple perforations ("microfractures") are placed 3 to 4 mm apart and about 4 mm deep into the subchondral bone to reach a zone of vascularization. The formation of a fibrin clot ("super clot") containing the desired pluripotential stem cells is stimulated. This clot then differentiates and remodels, resulting in a durable fibrocartilage repair tissue. The arthroscopic awls produce essentially no thermal necrosis of the bone compared to hand-driven or motorized drills. In contrary to drills, it is possible with differently curved awls to reach and treat every area of the knee joint or even of the upper ankle or shoulder joint. Between 1992 and 1998 this technique has been used in 351 cases. 162 patients were interviewed with a questionnaire with respect to their subjective judgement of health between 3 and 6 years (mean 4.4) after operation. Pain was the parameter with the greatest improvement. 78% of the patients improved, 18% remained unchanged and 4% were worse. Microfracture is an advisable option for the treatment of full thickness chondral defects.

[New developments in surgery of the knee joint (II)]. / Neue Entwicklungen in der Kniegelenkschirurgie (II).

Due to the recent fitness craze and increased interest in leisure activities, there has also been a dramatic rise in injuries to the anterior cruciate ligament (ACL) of the knee. Thanks to the introduction of arthroscopic surgery techniques, the number of ACL operations is increasing, frequently with insufficient results caused by technical errors during the operation. New methods are therefore necessary in order to assure quality. Traumatic or degenerative lesions to the cartilage are relevant causes of loss of working hours and permanent disability. The development of new therapeutic methods is focused on interest in orthopaedic research. An important cause for lesion of the cartilage is a partial or total rupture of the meniscus as a result of traumatic or degenerative processes. Today refixation of a torn meniscus is unfortunately not performed enough. New fixation techniques have been developed to facilitate preservative meniscal surgery. Finally, accelerated and functional rehabilitation programs have significantly contributed to improve the outcome of knee surgery.

Biomechanical analysis of knee hyperextension and of the impingement of the anterior cruciate ligament: a cinematographic MRI study with impact on tibial tunnel positioning in anterior cruciate ligament reconstruction.

This study analyzed the interaction between the anterior cruciate ligament (ACL) and the intercondylar notch roof (INR) in hyperextension of the knee using magnetic resonance cinematography. Cinematographic image series of 15 knees were investigated. Two independent observers identified the image that displayed the beginning of contact between the ACL and the INR. They determined knee extension on this image and on the image that displayed maximum hyperextension of the knee. Correlations between a variable representing impingement and the inclination angle of the INR, the anterior laxity of the knee, and full hyperextension were examined. Theoretical, impingement-free tibial tunnel positions for the knees were calculated as a percentage of the anteroposterior tibial width. All ACLs of the knees in this study made contact with the INR. The average extension angle at the beginning of impingement was -6.3 +/- 3.8 degrees. There were significant correlations between impingement and maximum manual displacement as measured with the arthrometer (r = 0.77; P < 0.001), maximum hyperextension (r = 0. 67; P = 0.007), and notch roof angle (r = -0.73; P = 0.002). There were biomechanically acceptable tunnel positions for all knees but one. Hyperextension is physiologically associated with impingement of the ACL. In uninjured knees there was a correlation between ACL impingement and hyperextension, inclination of the INR, and maximum manual displacement of the tibia. Impingement free tibial tunnel positioning is possible in most knees without notchplasty.

Transsynovial kinetics of lonazolac and its hydroxy metabolite in synovitis patients.

OBJECTIVE: The study was designed to characterize the synovial distribution profiles and kinetics of the non-steroidal antiinflammatory agent, lonazolac, in patients with synovitis after multiple dosing with 300 mg tablets of lonazolac calcium salt. METHODS: Forty patients (36 male, 4 female) aged 21 to 50 years (mean: 38+/-9 years) undergoing arthroscopy of the knee joint for surgical reasons were given 7 total doses of drug administered as 300 mg oral tablets of lonazolac-calcium taken twice daily. Patients were assigned to one of 4 treatment groups (n = 10) in which arthroscopy was carried out 1, 2, 6, or 12 h after the seventh lonazolac dose. Samples of blood, synovial fluid, and synovial membrane were obtained during each operation and used to determine total concentrations of lonazolac and its main metabolite in plasma and synovial fluid by HPLC assay with UV detection. Free lonazolac concentrations in body fluids were determined after ultrafiltration by the same HPLC technique using a fluorescence detector. Tissue concentrations were assayed after additional steps using solvent and solid phase extractions. Total protein contents in plasma and synovial fluid were measured spectrophotometrically. RESULTS: Plasma drug levels were highest at 1 hour after dosing with mean peak concentrations of 1.8 mg/l total lonazolac, 1.2 mg/l total metabolite, and 9 microg/l free lonazolac. Profiles indicated a biphasic decline. Concentration vs. time profiles in synovial fluid were flattened compared to plasma profiles with mean peak values of 440 microg/l total lonazolac, 370 microg/l total metabolite, and 7 microg/l free lonazolac attained 2 hours after dosing. The mean unbound fraction of lonazolac was higher in synovial fluid (1.9%) compared to plasma (0.7%). Transsynovial partition coefficients increased continuously during a dosing interval from 0.16 to 3.15 for total lonazolac and from 0.56 to 5.05 for free lonazolac. Mean total protein contents for each group of patients ranged from 70 to 76 g/l for plasma and 32 to 42 g/l for synovial fluid. Total drug concentrations in synovial membrane were highest in tissues obtained 1 hour after dosing with mean values of approximately 1.0 microg/g dry weight. Tissue samples obtained at later times indicated that lonazolac profiles in tissue more closely resemble profiles obtained for plasma than for synovial fluid. Protein concentration ratios (synovial fluid : plasma) were between 0.45 and 0.58. Except for the absorption phase, transsynovial drug partition coefficients were always higher than the protein concentration ratios. CONCLUSIONS: Protein content is not an important factor for drug partition into inflamed joints after multiple dosing with lonazolac. Lonazolac distributes well into synovial fluid with therapeutically effective concentrations of unbound drug measured within 2 hours after dosing. Total lonazolac levels in synovial fluid exceed those measured in plasma at 6 to 12 hours after administration.

Percutaneous repair of Achilles tendon rupture. Immobilization versus functional postoperative treatment.

Between 1987 and 1992, 48 patients with ruptured Achilles tendons were operated on using a standardized microinvasive technique; 30 patients underwent functional postoperative treatment, whereas 18 underwent conventional cast immobilization. Validated tests and a specially designed instrument for measuring strength and endurance were used for followup examinations. Patients undergoing functional postoperative treatment were hospitalized for shorter periods and lost fewer days from work than those in the cast group. Tests of ankle mobility showed more pronounced limitations of plantar flexion in cast immobilized versus functionally treated patients. Patients in the cast group also did less well on maximal one leg tiptoeing. Percutaneous Achilles tendon repair with functional postoperative treatment and early full weightbearing was associated with significantly less severe limitations of calf muscle work by the injured leg than postoperative cast immobilization. The rerupture rate was no higher than after cast immobilization, but lower than after open surgical repair or conservative functional treatment alone. Unlike those undergoing conservative functional treatment, patients need not wear special boots at night or be observed by ultrasound studies at regular intervals. Because the procedure can be done on an outpatient basis and because patients lose significantly fewer days from work than those immobilized in a cast, cast immobilization after Achilles tendon suture repair is no longer justified.

Combination of cold and compression after knee surgery. A prospective randomized study.

The objective of this study was to investigate the effect of continuous long-term application of a combined cooling and compression system (Cryo/Cuff, Aircast Inc., Summit, New Jersey, USA) on postoperative swelling, range of motion (ROM), pain, consumption of analgesics, and return of function after anterior cruciate ligament (ACL) reconstruction. We compared the cold-compression system with traditional ice therapy. There were 44 patients in the series (aged 15-40 years) who were randomly assigned to a control group (ICE) or a study group (CC). The ICE group consisted of 23 patients (aged 24.2 +/- 4.5 years); the CC group consisted of 21 patients (aged 24.8 +/- 5.6 years). The ICE group received ice bags postoperatively; the CC group was provided with the Cryo/Cuff during the 14-day hospital stay. Girth, ROM, pain score (visual analog scale), and consumption of analgesics were determined on postoperative days 1, 2, 3, 6, 14, and 28. Twelve weeks after surgery, isokinetic testing was performed, and the functional knee score was determined. In the CC group, significantly less swelling was observed (P < 0.035). These patients also reported less pain and had a significantly reduced consumption of analgesics (P < 0.04). On all examination days, ROM in the CC group was up to 17 degrees greater than in the ICE group (P < 0.02). The functional knee score was significantly increased in the CC group (P = 0.025). The results from our study document the advantages of continuous cold-compression therapy over cold alone following ACL reconstruction.

[Biological, biomechanical and clinical concepts of after-care following knee ligament surgery]. / Biologische, biomechanische und klinische Konzepte zur Nachbehandlung nach Bandeingriffen am Knie.

Rehabilitation of the anterior cruciate ligament (ACL) continues to be a topic of intense interest among surgeons and therapists. Numerous experimental studies have demonstrated that motion and a certain amount of stress are necessary for ligament healing. In experimental and clinical studies closed kinetic chain exercises have been proven to be safe already in the early phase of rehabilitation. Since 1987, over 2900 patients who have undergone ACL reconstruction using the central one-third of the bone patellar tendon bone graft have followed our accelerated rehabilitation protocol. Follow-up of the patients reveals early return to athletic activity and maintenance of long-term stability. Our 1987 accelerated rehabilitation program continues to be modified, with less constraints placed on the postoperative patient in our present rehabilitation protocol. Past patient non-compliance to previously established protocols still yielded excellent results that demanded further investigation. Gradually we developed a four-phase rehabilitation protocol. The initial phase encompasses the preoperative period with the goal of resolving swelling and regaining full motion. The second phase involves the initial two weeks post ACL reconstruction and focuses primarily on wound healing, full extension, control of swelling, and leg control. The third phase (two to five weeks) involves increasing flexion, developing a functional gait, and resuming activities of daily living. The fourth phase (> five weeks) identifies a safe return to competitive athletics. With this accelerated rehabilitation protocol a decreased postoperative morbidity was noted without jeopardizing the long term stability of the ACL reconstructed knee.