[Clinical outcome, 6 years after robot assisted hip endoprostheses implantation--a prospective study]. / 6-Jahres-Ergebnisse nach roboterunterstützter Hüftendoprothesenimplantation--eine prospektive Studie.

AIM: In our prospective study we evaluated the clinical and radiological results of 36 patients who had a robot-assisted implantation of a cementless hip endoprosthesis. METHOD: All patients underwent a standardised examination preoperatively, 1 year after the operation and 6 years postoperatively. We evaluated the pain of the patients with the help of a visual analogue scale, the range of motion of the hip joint and subjective and objective parameters according to the Harris hip score and the Merle d'Aubigné score. With X-rays loosenings and movement of the stems were evaluated. All patients were operated by the same team. RESULTS: The clinical results were very good. A highly significant pain reduction could be documented. We also saw a significant improvement in the range of motion and the hip scores. In 1 case a loosening of the stem happened after 5 years, in another patient the stem broke out a few days after implantation. The reason for this was not a mistake of the robot but the wrong preoperative planning. Other complications were not observed. CONCLUSION: Considering the good biochemical results in the literature, our study suggests good long-term results after robot-assisted hip surgery. The drawbacks and complications of robot-assisted hip surgery, which were documented especially in the popular press, cannot be confirmed.

[Modified percutaneous balloon kyphoplasty at osteolysis of 11th thoracic vertebra and communication with the spinal canal. Case report and review of the literature]. / Modifizierte perkutane Ballonkyphoplastie bei Osteolyse des BWK11 und Kommunikation mit dem Spinalkanal. Ein Fallbericht und Aufarbeitung des Schrifttums.

This paper presents the case report of a 67-year-old man who came to our hospital suffering from severe osteolysis of the 11th thoracic vertebral body. The patient has been suffering from renal cell carcinoma for 2 years. During a routine control the above-mentioned lesion was found by chance. A few days later pain started in the thoracolumbar region. Treatment was intended to be palliative. Therefore, we looked for an option to stabilize the vertebral body as minimally invasive as possible. Because of a destroyed trailing edge of the vertebra, "normal" kyphoplasty was not possible. For this reason, we performed a modification, using one filled balloon as a kind of curtain between the vertebral body and spinal canal. With this technique we achieved an optimal filling of the destroyed vertebral body with cement, without any leakage. Two days postoperatively, the patient could leave our hospital without any pain symptoms.

[Primary rotatory stability of hip endoprostheses stems after manual and robot assisted implantation]. / Primäre Rotationsstabilität von roboterunterstützt und manuell implantierbaren Hüftendoprothesenschäften.

AIM: In our study we compared the primary rotatory stability of hip endoprostheses which were implanted with the help of a robot with that of manually implanted stems. METHOD: We examined three different types of prosthesis-stems: Osteolock (Stryker-Howmedica), CBC (Mathys), Excia (Aesculap). Furthermore, we examined two types of prostheses which could not be implanted with a robot (Sl-Plus/Endoplus; Hipstar/Stryker-Howmedica). 10 stems of each prosthesis type were implanted in identical polyurethane foam blocks; 5 of them were implantated manually, 5 with the help of a robot (CASPAR, URS-Ortho). After implantation, a defined rotatory stress was put on the stem with the help of a torquing machine. The torsional moment which was necessary until the stem broke out of the foam was documented with the help of special software. RESULTS: In all types of prostheses the use of the robot system led to a higher rotatory stability compared to the manual group. Among the three tested types of prosthesis stems, the CBC stem is significantly more stable for rotatory forces after robot-assisted implantation compared to the other two types. After manual implantation there was no difference in stability between the different stems. The Zweymüller stem and the Hipstar prosthesis did very well, even in comparison to the robot-implanted group. The results of the Zweymüller stem and the robot-implanted CBC Stem were similar, and a significantly higher rotatory stability of the Hipstar prosthesis compared to every other stem was observed. CONCLUSION: Using a robot, the rotatory stability of hip endoprostheses can be improved. However, the design of the stems seems to be even more important for the stability than the implantation technique.

[Primary rotatory stability of robot-assisted and manually implanted hip endoprosthesis stems]. / Primäre Rotationsstabilität von roboterunterstützt und manuell implantierten Hüftendoprothesenschäften.

In our study we compared the primary rotatory stability of hip endoprostheses implanted with the help of a robot and manually implanted stems. We examined three different types of prosthesis stems: Osteolock (Stryker-Howmedica), CBC (Mathys), and Excia (Aesculap). Ten stems of each prosthesis type were implanted in identical polyurethane foam blocks: five were implanted manually and five with the help of a robot (CASPAR, URS-Ortho). After implantation, the stem was subjected to a defined rotatory stress. The torsional moment necessary to break the stem out of the foam was documented with the help of special software. The force-displacement diagrams after robot-assisted implantations were homogeneous for each type of prosthesis. After manual preparation, the diagrams were very inhomogeneous. The rotatory test also showed very consistent results for the robot-implanted stems. The range of results after manual implantation was much higher. In all types of prostheses the use of the robot system led to a higher rotatory stability compared to the manual group. The CBC stem was most stable for rotatory forces after robot-assisted implantation compared to the other two types. After manual implantation there was no difference in stability between the different stems.

[Extravertebral cement drainage with occlusion of the extradural venous plexus into the vena cava after vertebrobplasty. Case report and review of the literature]. / Extrakorporaler Zementabfluss mit Füllung des extraduralen Venenplexus bis in die V. cava nach Vertebroplastie. Fallbericht und Aufarbeitung des Schrifttums.

This paper presents the case report of an 88 year old female who came to hospital suffering from a severe lower back pain. Ten days before, she had undergone a vertebroplasty with injection of cement into lumbar vertebra 3 because of an osteoporotic fracture. This treatment did not result in a reduction of the lower back pain, which was the main reason for the procedure. However, the patient claimed to have increasing pain radiating to her left leg. Furthermore, she suffered from numbness of her left leg. Clinical examination showed a lack of power in this leg according to hip flexion with a degree of 3/5. X-ray examinations showed paravertebral cement particles and led to the suspicion that the paravertebral cement had caused nerve root compression. MRI and CT myelography showed that the cement had drained into the intraspinal, extradural venous plexus (Batson's plexus). The plexus was filled out with cement between L2 and L5 on both sides. There was nearly no cement in the fractured vertebra L3, but cement had also run onto the paravertebral veins up to the vena cava, which was also involved. The cemented veins had led to a stenosis of the neuroforamina L2 and L3 on the left side. The result was compression of left L3 nerve root. After consulting with our vascular surgeons, we decided on a non-operative treatment. We prescribed a lumbar brace as external stabilisation and as an antithrombotic treatment we gave the patient weight adapted low molecular weight heparin.

[Dislocated fracture of the lesser trochanter with malrotation of the stem after robot assisted implantation of a cementless hip prosthesis: a casuistic report]. / Abbruch des Trochanter minor und Einsinken des Prothesenschafts nach roboterunterstützter Hüftendoprothesenimplantation. Ein Fallbericht und Aufarbeitung des Schrifttums.

This paper presents the case of a 63 year old female with a severe coxarthrosis. She got a robot assited implantation of a cementless hip prosthesis (Osteolock, Stryker-Howmedica, Mühlheim). As operation robot the CASPAR-System (Orto-Maquet, Rastatt) was used. Initially, the clinical progress of the patient was fine. She was nearly painfree within 14 days and showed an acceptable range of motion in the operated joint (flexion/ extension 90 degrees /05 degrees /00 degrees ). She was mobilized with crutches and 15 kg weight bearing at the operated leg. 3 weeks postoperative the patient complaint about increasing pain without trauma or intensification of the weight bearing. X-rays showed not only a dislocated fracture of the lesser trochanter, but also a sinking combined with a malrotation of the stem. A revision operation was necessary,where we implanted a cemented stem. Now clinical progress was completely satisfying.

Spontaneous fusion of 'os acetabuli' after triple pelvic osteotomy.

In acetabular dysplasia, an overloading of the acetabular rim can cause a stress fracture, creating an 'os acetabuli', or a lesion of the acetabular labrum. At puberty, the os acetabuli seems to be the epiphysis of the os pubis. We present the case of a 14-year-old girl with acetabular dysplasia and spontaneous fusion of an 'os acetabuli' after biomechanical correction by triple pelvic osteotomy. Our report supports the correctness of the biomechanical principle: reorientation of the acetabulum results in a better coverage of the femoral head, reduces the stress at the acetabular rim, shifts the os acetabuli out of the stress region, and may allow union of the bony fragment with the acetabulum.

[Mechanisms and prevention of kitesurfing injuries]. / Verletzungsmechanismen und Verletzungsprävention beim Kitesurfen.

Aim of this study was to analyse the mechanisms of kitesurfing injuries. For this purpose we performed a survey among 72 kitesurfers in the north of Germany. 31 accidents have been registrated among all 72 athletes during the 2001 season. 3 additional accidents occurred where a windsurfer got injured. 5 athletes had medium injuries such as fractures, all remaining athletes presented with minor injuries, that did not require medical treatment. The incidence of medium kite injuries was 1/1000 hours; the incidence of minor kite injuries was 5/1000 hours. The most common injury mechanism was a direct trauma against things such as stones and boats lying on the beach. The most common situation in which the injury occurred was the lost of control about the kite on the beach or close to the beach due to technical mistakes of the surfer, oversized kites, or the wind conditions (onshore wind, overpower). Further injuries occurred due to collisions with windsurfers or sailing boats. Kitesurfing is a new rapidly growing sport. To date the risk potential of this new sport is unclear. The analysis of the injury mechanisms allows conclusion regarding the prevention of kitesurfing injuries.

Treatment of the athlete with multidirectional shoulder instability.

Treatment of multidirectional instability in the athlete continues to be a challenging problem. Nonoperative treatment remains the initial treatment of choice in most athletes. However, some patients will fail nonoperative treatment and might require operative intervention. An open capsular shift procedure is indicated in nonoverhead athletes, most contact athletes and in most revision situations. However, the advances in thermal treatment of the capsule have made arthroscopic electrothermal capsulorrhaphy increasingly attractive as an alternative to the open approach for the primary treatment of multidirectional instability. Longer follow-ups will be necessary before definitive statements can be made regarding the arthroscopic techniques.

[Polyethylene content and cell size of foreign body giant cells in aseptic hip prosthesis loosening--a histomorphometric study]. / Polyethylenbeladung und Zellgrösse von Fremdkörperriesenzellen bei der aseptischen Hüftendoprothesenlockerung--Eine histomorphometrische Untersuchung.

INTRODUCTION: In aseptic loosening of cementless hip arthroplasty polyethylene particles are phagocytized by macrophages and foreign-body giant cells. This initiates an osteolytic cascade. In this study, the authors investigated if there are correlations between the size of foreign-body giant cells and the polyethylene loading and number of intracellular particles as determined by light microscopy. MATERIAL AND METHOD: Histological specimens were processed from tissues retrieved during revision surgery of 7 cases of cementless hip arthroplasty which had become aseptically loose. The specimens were analyzed by histolomorphology and histomorphometry. The cell size, polyethylene loading and intracellular particle number of 111 foreign-body giant cells were determined. A regression analysis was performed to investigate if there was a correlation between these variables. RESULTS: The mean cell size was 1417 +/- 487 micron 2, the mean polyethylene loading was 49 +/- 42 micron 2 and the mean intracellular particle number was 10.4 +/- 5.4. The cell size correlated with both the intracellular particle number (r = 0.25) and the polyethylene loading (r = 0.39). CONCLUSIONS: In the cellular reaction to polyethylene particles in aseptic loosening of cementless total hip arthroplasty, the size of foreign-body giant cells correlates with intracellular polyethylene loading and intracellular polyethylene particle number as determined by light microscopy. The presence of large foreign body giant cells might be associated with a high particle load of the tissue and a high osteolytic activity.

[Injury mechanisms in windsurfing regatta]. / Verletzungsmechanismen bei Regattawindsurfern.

In a retrospective study, we evaluated the injuries of 44 semi-professional competitors for the German Windsurf Cup, which were suffered from during one windsurfing season. This Cup is the national qualification tour for the annual "production fun board world championship". The subjects, participating in our study were randomly chosen. There were no surf-specific differences between the two groups. The average age was 24.63% had competitive surfing as their hobby, 37% were professional or semi-professional board sailors. The subjects surfed an average of 85 days in 1995. 23 (52%) windsurfers did not get hurt during the entire season. 21 (48%) of them got injured during the 1995 windsurf season. This is an incidence of only one injury per 174 windsurfing days. Only three windsurfers were injured during a competition. The other 18 occurred during training sessions. Most accidents happened because of an overpower situation, i.e. the sail was too big for the wind force (43%), or through negligence on the part of the windsurfer (19%). The most frequent type of the accident was the so called catapult crash (57%). The most common injuries were ligament ruptures of the lower leg (33%) and head burst wounds (19%). Compared with other competitive fun sports (e.g. snow boarding), windsurfing has a lower injury risk. In regard to the injury mechanisms, prophylactic recommendations are made.

[Arthroscopic therapy of septic arthritis. Surgical technique and results]. / Arthroskopische Therapie der septischen Arthritis. Operative Technik und Ergebnisse.

UNLABELLED: In a retrospective study we evaluated 22 patients suffering from septic arthritis, who were treated arthroscopically. We operated 15 male and 7 female patients with an average age of 38.1 years (4-70). There were 16 knee joints, 3 elbows, 2 shoulder and one hip. Arthroscopic therapy was indicated when the typical clinical signs and blood-chemical inflammation findings (increased ESR and CRP) were present and when bone involvement was excluded. Arthroscopic treatment was performed according to the local findings and the grade of infection. It consisted of lavage, debridement, synovectomy, and the application of an antibiotics-containing collagenous fleece. Additionally systemic antibiotics were applied peri- and postoperatively. None of our patients got a secondary osteomyelitis. 20 patients could be cured with a single operation, two patients had to be revised several times. Excluding one patient, in every patient the infect could be cured with a total restitution of the previous range of motion. CRP was the most sensitive parameter. CONCLUSION: Considering the advantages of arthroscopic surgery and the good results in infection therapy, it should be recommended as a method as soon as joint infection is suspected.

[Proprioceptive abilities of surgically and conservatively treated knee joints with injuries of the cruciate ligament]. / Propriozeptive Fähigkeiten bei operativ und konservativ behandelten kreuzbandinsuffizienten Kniegelenken.

UNLABELLED: In the present study we evaluated proprioceptive capabilities of the knee joint with a balance test and correlated these findings to parameters which document mechanical stability. We compared 8 conservatively treated and 12 surgically treated patients with ACL-deficient knee joints with a control group of 12 subjects. The balance test was performed with a Kistler force plate. Both the conservatively treated and the surgically treated patients showed significantly higher deviations of their centre of gravity than the control group. This was true not only for the injured leg but also for the noninjured contralateral leg. The differences were most remarkable when comparing the entire distance of centre of gravity deviations during 10 s. Additionally, the conservatively treated patients interrupted the test procedure significantly more frequently than the other two groups. We were not able to document any correlation between proprioceptive function and parameters for joint stability such as anterior drawer, Lachman, pivot shift and KT-1000 measurements. CLINICAL SIGNIFICANCE: In patients with conservatively or surgically treated ACL tears the rehabilitation of proprioceptive capabilities is mandatory both for the injured leg and for the noninjured contralateral leg in order to restore the function of the lower extremities. Reconstruction of passive stability alone is not sufficient.

[Proprioceptive capacities of patients with retropatellar knee pain with special reference to effectiveness of an elastic knee bandage]. / Propriozeptive Fähigkeiten bei Patienten mit retropatellarem Knieschmerz unter besonderer Berücksichtigung der Beeinflussung durch eine elastische Kniebandage.

In the presented study, knee joint proprioception of 43 patients with a patellar pain syndrome of the knee joint was evaluated. In a control group, the proprioception of 30 healthy volunteers with clinical and an-amnestic inconspicous knee joints was examined. We tested the proprioceptive capability of the subjects with a passive angle reproduction test. Additionally, all knee joints were measured with and without an elastic knee bandage. The patient group showed significant deterioration of angle reproduction capability (13.2 degrees +/- 6.1 degrees) compared to the control group (7.8 degrees +/- 2.8 degrees). After applying an elastic knee bandage, the angle reproduction capability significantly improved to 9.2 degrees +/- 4.5 degrees. Proprioception of the contralateral, noninvolved knee joint in the patients (11.6 degrees +/- 6.3 degrees) was worse compared to the control group. Applying an elastic knee bandage did not significantly improve the proprioception of the uninjured knee joint.

[Proprioceptive deficits of the knee joint after rupture of the medial meniscus]. / Propriozeptive Defizite des Kniegelenks nach Ruptur des medialen Meniskus.

We assessed knee joint proprioception in 23 patients with an isolated lesion of the medial meniscus. Thirteen patients were tested prior to their arthroscopic operation, and 10 patients were examined after partial arthroscopic resection of the injured meniscus. As a control group we evaluated 30 healthy volunteers with clinically inconspicious knee joints. For documentation of the proprioceptive capabilities we performed an angle reproduction test. Additionally the subjects were tested with and without an elastic knee bandage, to test the influence of such a bandage on knee joint proprioception. Our results showed that preoperatively proprioception was significantly less good than in the control group. We found no influence of the knee bandage on the proprioception of the injured knee. The postoperative group of patients showed significantly better proprioceptive capability than the preoperative patients. The postoperative results did not differ significantly from those of the control group.

[Modification of proprioceptive ability of knee joints with primary gonarthrosis]. / Beeinflussung der propriozeptiven Fahigkeit von Kniegelenken mit einer primären Gonarthrese.

In the study presented, knee joint proprioception of 17 patients with primary degenerative joint disease of the knee joint was evaluated. As a control group, the proprioception of 30 healthy volunteers with clinical and anamnestically inconspicuous knee joints was examined. We tested the proprioceptive capability of the subjects with an angle reproduction test. Additionally, all knee joints were measured with and without an elastic knee bandage. The study showed significantly more deterioration in knee joint proprioception in patients with gonarthrosis than in the control group. Even the proprioception of the contralateral, healthy knee joint was worse than the results of the control group. However, after using an elastic knee bandage, significant improvement in the proprioceptive abilities of the injured knee joint was documented.

[Proprioceptive capacity of the knee joint area in patients after rupture of the anterior cruciate ligament]. / Propriozeptive Fähigkeiten im Bereich des Kniegelenks bei Patienten nach vorderer Kreuzbandruptur.

In 30 healthy volunteers with clinically inconspicuous knee joints the proprioception of the knee joint was evaluated by an angle reproduction test. With the same set-up we documented the effect of an elastic knee bandage. We could not document any differences between the left and the right knee joint or between men and women, but at the mid-range of motion, proprioception was worse compared to the end range of motion. The applied elastic knee bandage significantly improved the position sense. Additionally 25 patients with an isolated rupture of the anterior cruciate ligament were evaluated. Fourteen patients were examined preoperatively 11 after operative ACL reconstruction. Preoperatively proprioception was significantly poorer than in the control group. We were able to show a positive influence of a knee bandage on the proprioception of the injured knee as well. Patients after ACL reconstruction showed no significantly better proprioception than the preoperative group.

Proprioception of knee joints with a lesion of the medial meniscus.

We assessed knee-joint proprioception in 23 patients with an isolated lesion of the medial meniscus. Thirteen patients were tested prior to their arthroscopic operation, and 10 patients were examined after partial arthroscopic resection of the injured meniscus. As a control group we evaluated 30 healthy volunteers with clinically normal knee joints. For documentation of the proprioceptive capabilities we performed a special angle reproduction test which was described in the literature. Additionally the subjects were tested with and without a knee bandage, to test its influence on knee-joint proprioception. Our results showed that preoperatively a significant deterioration in proprioception was present compared with the control group. We could not find any influence of the knee bandage on the proprioception of the injured knee. The postoperative group of patients showed a significantly better proprioceptive capability compared to the preoperative patients. The postoperative results also did not show any significant difference as compared to those of the control group.