[Ankle arthrodesis - clinical, radiological and biomechanical aspects with special regard to the adjacent joints]. / Die Arthrodese des oberen Sprunggelenks - klinische, radiologische und biomechanische Aspekte unter besonderer Berücksichtigung des unteren Sprunggelenkkomplexes.

BACKGROUND: Arthrodesis as well as total arthroplasty are well established but controversially discussed treatment options for end-stage osteoarthritis of the ankle joint. For guidance concerning the significance of both surgical procedures we have correlated our clinical, radiological and biomechanical data with an up-to-date literature review. MATERIAL AND METHODS: 15 patients after arthrodesis because of an isolated end-stage osteoarthritis of the ankle joint were followed clinically and radiologically 4 (1.9-8.8) years after surgery. To evaluate the outcome, different scores (AOFAS, Kellgren and Lawrence) were used. In the second part of the study a dynamic foot model was implemented to simulate a foot strike in vitro utilising a cadaver foot. By controlling 6 extrinsic tendons via steel cables, a hydraulic force application and a moving ground plate, a foot strike was simulated. Intraarticular compression load was measured in the talonavicular and calcaneocuboid joints with pressure-sensitive foils. RESULTS: The mean AOFAS score for the subcategory pain was 28 ± 12 points. In the subcategory function the patients had a mean score of 38 ± 9 points summing up to a mean total AOFAS score of 66 ± 18 points. Six patients showed radiological evidence of degeneration of the talonavicular joint. For these patients the Kellgren and Lawrence score was 2.3 (1-4) points higher than for the opposite side. Concerning the subtalar joint in 6 patients the Kellgren and Lawrence score was 1.6 (1-3) points higher compared to the non-surgery side. In contrast we noted only one case with degeneration of the calcaneocuboid joint. The native trial utilising the foot model revealed a continuous rise of load transmission in both parts of the Chopart joint. After performing an arthrodesis, load transmission rose significantly in the second half of the foot strike concerning the talonavicular joint whereas the calcaneocuboid joint showed a decreased transmission of load. CONCLUSION: Referring to published data complication rates after ankle arthrodesis are lower compared to total ankle arthroplasty whilst adjacent joint degeneration of the subtalar and talonavicular joints is more common.

[Problem cases of metatarsalgia]. / Problemfälle bei Metatarsalgie.

Metatarsalgia is characterized by pain under the metatarsal heads and is a very common cause of foot pain among adults. Symptoms can be isolated or in combination with accompanying deformities occurring in the forefoot and/or hindfoot. In the foreground of the treatment is the exhaustion of conservative forms of therapy to minimize the symptoms of local pressure increase and callus under the metatarsal heads. In addition, various surgical methods are available, such as corrective osteotomy of the metatarsal bone, soft tissue interventions and the correction of associated deformities. The indications for surgical intervention should be made with caution in order to avoid failures and complaints persisting after surgery. The most common problems are an inadequate indication for surgery, technical problems and insufficient postoperative treatment.

[General operative technique of the foot and ankle]. / Allgemeine Operationstechnik an Fuss und Sprunggelenk.

Soft tissue coverage of the foot is more critical than in other orthopedic operation areas. In addition, the foot bears the most mechanical load during walking. Therefore, meticulous operative techniques are of special relevance and tourniquet times must be kept as short as possible. Unnecessary soft tissue dissection must be avoided and electrocautery is not necessary and only damages tissues. Sharp retractors should not be used for the same reason. Osteotomy in three dimensions heals more reliably and inexpensive standard implants can generally be used. Capillary perfusion must be checked following the procedure. A compression dressing avoids postoperative bleeding and swelling. Usually full weight-bearing is possible in a flat postoperative shoe. Postoperative wound coverage must be dry and without ointments or powders.

[Failures of hallux valgus surgery]. / Fehlschläge in der Hallux-Valgus-Chirurgie.

More than 150 corrective procedures for hallux valgus exist and an incorrect choice of procedure leads to insufficient correction. Distal first metatarsal osteotomy cannot correct large deformities and degenerative changes at the metatarsophalangeal joint impede functional recovery. Incongruence of the joint must be corrected during surgery. Recurrence is most often caused by insufficient correction, especially of the first metatarsal bone. Overcorrection is often due to technical problems with the initial metatarsal osteotomy. This also applies to insufficiency of the first ray due to shortening or dorsal angulation. Partial first metatarsal head necrosis occasionally occurs but complete necrosis is rare. Non-union is mostly caused by incorrect osteosynthesis. During postoperative treatment the hallux must be held in the correct position to avoid failure.

[Recurrent hammer and clawed toes after surgical correction]. / Rezidive nach Korrektur von Hammer- und Krallenzehen.

Symptomatic lesser toe deformities should be corrected if conservative therapy is exhausted or no longer seems appropriate. Prevention of recurrence starts with the correct indication for the appropriate surgical procedure. The occasional difficult question of the cause of the deformity is crucial in this context. A correct surgical technique and appropriate after-care reduces the risk of recurrence. Due to tensed bony and soft-tissue conditions, revision surgery of the forefoot is challenging. If a revision becomes necessary, the cause of recurrence must be re-examined. This paper explains the appropriate indications and surgical techniques for correction of lesser toe deformities. Subsequently, specific postoperative complications and their management are discussed in detail.

[Chronic brucellosis: a rare cause of septic loosening of arthroplasties with high risk of laboratory-acquired infections]. / Brucellose: eine seltene Ursache für Endoprothesenlockerungen, einhergehend mit einem hohen Infektionsrisiko für Labormitarbeiter.

Brucella spp. are a main contributor to morbidity in endemic countries, especially in the Near and Middle East and the Mediterranean. However, in most western industrialised countries, cases are rare. Here, we report the case of a previously unrecognised chronic brucellosis with subsequent laboratory-acquired infection. A 64-year-old female presented to the orthopaedic department with loosening of her knee prosthesis after total knee arthroplasty five years earlier. Bacterial cultures were obtained in a preoperative puncture of the affected joint. About two weeks after replacement of the prosthesis bacterial growth was detected by chance in the preoperative culture and Brucella melitensis was diagnosed, whereas the intraoperative swab was negative. Serology revealed a chronic brucellosis while blood cultures were negative. Antibiotic treatment with rifampin and doxycycline was initiated. Two months later, a 32-year-old male physician who was involved in identifying the bacterial pathogen began to suffer from night sweats, weight loss and elevated temperatures. Another 4 weeks later, he developed hip pain and synovialitis. At that time, blood cultures and urine specimens were positive for Brucella melitensis. The serological results were consistent with acute brucellosis. In many European and North American countries, especially Germany, Brucella spp. are rarely isolated from clinical microbiological specimens and present a considerable risk for laboratory-acquired infections.

A prospective randomized study of minimally invasive total knee arthroplasty compared with conventional surgery.

BACKGROUND: Despite intense debate regarding whether minimally invasive techniques for total knee arthroplasty improve clinical outcomes over standard techniques, few prospective randomized trials addressing this debate are available in the literature. We therefore designed this multicenter study to assess the overall safety and effectiveness of a minimally invasive approach without the use of computer navigation in comparison with conventional knee arthroplasty. METHODS: We prospectively randomized 134 patients (101 women and thirty-three men, with an average age of 70.1 years) to undergo surgery for total knee arthroplasty with use of either minimally invasive knee instruments (sixty-six patients) or a standard approach (sixty-eight patients). The follow-up period was one year. RESULTS: On the basis of our sample size, no significant difference was detected between the groups in any of the relevant clinical areas assessed: total range of motion, Knee Society total and function scores, and visual analog scores for pain and activities of daily living. Patients who underwent minimally invasive surgery had a longer mean surgical time (by 5.6 minutes) and had less mean blood loss (by 17 mL). Radiographic measurements demonstrated reliable implant positioning in both groups. Seven patients in each group had an adverse event related to their procedure. CONCLUSIONS: On the basis of the numbers, no significant advantage to minimally invasive total knee arthroplasty over a conventional technique was observed. Greater sample sizes and a longer follow-up period are required to fully determine the long-term safety and efficacy of this minimally invasive surgical technique.

[Loading of the tibiotalar joint and Chopart's joint following subtalar arthrodesis: dynamic cadaver study of 5 specimens]. / Belastung des oberen Sprunggelenkes und des Chopart-Gelenkes infolge der subtalaren Arthrodese: Untersuchung von 5 Kadaverpräparaten in einem dynamischen Modell.

AIM: Little has been known until now about biomechanical intra-articular changes in the condition of adjacent joints following subtalar arthrodeses. METHOD: We tested 5 cadaver specimens in a dynamic axially loaded foot model under computer-regulated load application on 9 extrinsic tendons of the foot regarding changes in load under native conditions and following an anatomically fixed subtalar arthrodesis. RESULTS: We saw an averaged native force transmission in the talonavicular joint of 87 N, increasing post-arthrodesis to 92 N. In the calcaneocuboid joint we measured an increase from 72 N to 74 N. For peak pressure, the increase was from native 3152 kPa to 3286 kPa in the talonavicular joint and in the calcaneocuboid joint we recorded a reduction from 3282 kPa to 3277 kPa. The effects are not striking from a statistical viewpoint. However, we observed a reduction in force from native 103 N to 90 N and in peak pressure from 4778 kPa to 4261 kPa in the ankle. When the ankle was divided into discrete zones in the sagittal and frontal planes there was no evidence of load displacement. CONCLUSION: Our measurements show that anatomically fixed arthrodeses of the talocalcanear joint do not lead to any striking increase in loads on adjacent joints. Any adjacent segment degeneration following subtalar arthrodeses may be the result of changes in joint kinematics or non-anatomically reconstructed hindfoot positions.

Chopart's joint load during gait. In vitro study of 10 cadaver specimen in a dynamic model.

BACKGROUND: Chopart's joint is fundamental to foot function. Until today, intra-articular force and peak pressure has not been investigated under dynamic conditions. METHODS: The study used a cadaver model to measure intra-articular force and peak pressure with electronic sensors. Force was applied to extrinsic tendons via cables attached to computer-regulated hydraulic cylinders. A ground reaction force of 350 N was simulated in a tilting angle- and force-controlled translation stage. RESULTS: We observed a characteristic rising curve with a peak during push-off for intra-articular force and peak pressure. The increase of intra-articular force at the talonavicular and calcaneocuboid joint from a low level at heel-on varies up to a maximum of 174 N/149 N and a peak pressure of 3877 kPa/3396 kPa, respectively, at push-off. We observed highest loading at the dorsal aspect of the talonavicular joint and the plantar aspect of calcaneocuboid joint. CONCLUSION: The highest loading on Chopart's joint is attained during push-off. We observe higher force and peak pressure on the medial column of the foot compared to the lateral column. The higher load of the dorsal aspect of talonavicular joint and plantar aspect of calcaneocuboid joint confirms the theory of a previous described locking mechanism for forceful push-off.

Changes in Chopart joint load following tibiotalar arthrodesis: in vitro analysis of 8 cadaver specimens in a dynamic model.

BACKGROUND: In the current discussion of surgical treatment of arthroses in the ankle joint, arthrodesis is in competition with artificial joint replacement. Up until now, no valid biomechanical findings have existed on the changes in intraarticular loads following arthrodesis. One argument against tibiotalar arthrodesis is the frequently associated, long-term degeneration of the talonavicular joint, which can be attributed to changes in biomechanical stresses. METHODS: We used a dynamic model to determine the changes in intraarticular forces and peak-pressure in the talonavicular joint and in the calcaneocuboid joint on 8 cadaver feet under stress in a simulated stance phase following tibiotalar arthrodesis. RESULTS: The change seen after arthrodesis was a tendency of relocation of average force and maximum pressure from the lateral onto the medial column of the foot. The average force increased from native 92 N to 100 N upon arthrodesis in the talonavicular joint and decreased in the calcaneocuboid joint from 54 N to 48 N. The peak pressure increased from native 3.9 MPa to 4.4 MPa in the talonavicular joint and in the calcaneocuboid joint from 3.3 MPa to 3.4 MPa. The increase of force and peak pressure on the talonavicular joint and decrease of force on the calcaneocuboid joint is statistically significant. CONCLUSION: The increase in imparted force and peak pressure on the medial column of the foot following tibiotalar arthrodesis, as was demonstrated in a dynamic model, biomechanically explains the clinically observed phenomenon of cartilage degeneration on the medial dorsum of the foot in the long term. As a clinical conclusion from the measurements, it would be desirable to reduce the force imparted on the medial column with displacement onto the lateral forefoot, say by suitable shoe adjustment, in order to achieve a more favourable long-term clinical result.

[Foreign blood saving measures in orthopedic surgery]. / Fremdblutsparende Massnahmen bei orthopädischen Eingriffen.

Major transfusion-free orthopaedic surgery can be performed successfully. This requires advanced planning, good routines and close collaborative team efforts. Since most blood saving techniques reduce blood usage by just 1-2 units, a series of integrated preoperative, intraoperative and postoperative blood saving approaches is required. These include preoperative autologous donation, erythropoietic support, acute normovolemic hemodilution, intraoperative autotransfusion, individualized assessment of anemia tolerance, meticulous surgical techniques and the use of pharmacologic agents for limiting blood loss. For various reasons, we do not recommend the transfusion of wound drainage. This article describes the various methods for bloodless medical care.

K-wire transfixation or distraction following the Keller-Brandes arthroplasty in Hallux rigidus and Hallux valgus?

A total of 118 feet with Hallux valgus and Hallux rigidus treated by the Keller-Brandes method were re-examined clinically and radiologically after 9.1 years (range: 1.7-24.3). Correction of the Hallux valgus angle was obtained from an average of 40 degrees to 23 degrees in the Hallux valgus group. Improvement in the postoperative range of motion was observed when the aftertreatment consisted of Kirschner-wire distraction instead of an axial Kirschner-wire transfixation. The patients who underwent Keller-Brandes surgery for Hallux valgus had less pain when the aftertreatment was carried out using an axial Kirschner wire, while those operated on for Hallux rigidus had less pain when the aftertreatment consisted of distraction. The percentage of satisfied or very satisfied patients with the cosmetic results of the Keller-Brandes arthroplasty was more than 66.7%. Patients with Hallux valgus and postoperative aftertreatment with Kirschner wire transfixation were the most satisfied patients, while patients with Hallux rigidus were very satisfied with the postoperative distraction. Our good results are comparable to those in other studies and confirm the success of the Keller-Brandes resection arthroplasty in Hallux valgus with osteoarthritis of the first metatarsophalangeal joint in older patients whose demand for movement is less, and in Hallux rigidus in less active older patients.

[Results of vacuum sealing therapy in joint infections]. / Ergebnisse bei der Behandlung von Gelenkinfektionen mit Vakuumversiegelung.

AIM: At present the vacuum sealing technique is acknowledged as a therapy for acute and chronic wounds. An acceleration of the healing process, due to the vacuum suction with occlusive wound dressing, leads to the shortening of a cost-effective medical treatment. This can be applied to wound treatment and infections of soft tissues, but even today there is only sparse information in this context about joint infections. METHOD: The results of therapy with the vacuum sealing technique in 68 patients with infections of the joints of an extremity or the trunk were analysed in a retrospective study without a control group. The importance of several patient-related factors for the medical treatment have been analysed. RESULTS: An adequate treatment of joint infections can be achieved even in the presence of endoprostheses or osteosynthetic material. The following factors have been found to be of significance for a prolonged medical treatment: diabetes mellitus (p=0.0052), obesity (BMI>25) (p=0.0458) and a preceding trauma (p=0.0457). CONCLUSION: The results confirm the value of the vacuum sealing technique following surgical debridement in combination with resistance tested antibiotic treatment, as a sufficient therapy for joint infections, even in patients with an endoprosthesis. This procedure leads to a safe treatment of the joint infection, combined with a good function of the treated joint, good patient comfort and a short duration of the therapy.

[Prediction of the location of the centre of rotation of the hip joint external landmarks]. / Die Bestimmbarkeit des Hüftrotationszentrums anhand palpabler Landmarken des Beckens.

AIM: The object of this study was to develop a new method to predict the location of the centre of rotation of the hip joint reasonably accurately. METHOD: We collected the coordinates of palpable bony landmarks in 50 patients, 25 males and 25 females, using CT scans to predict the physiological location of the centre of the hip joint centre. RESULTS: The centre of the hip was located, on average, at 12% (+/- 2.9) of the inter-ASIS (anterior superior iliac spine) distance medial, 33% (+/- 3.9) distal and 19% (+/- 2.7) posterior to the anterior superior iliac spine (ASIS). CONCLUSION: Knowledge of the physiological centre of rotation of the hip may be useful in navigation of the cup in total hip arthroplasty.

[Postoperative autologous transfusion from blood drainage after total hip joint arthroplasty--how much value is really there?]. / Postoperative Rücktransfusion von Drainageblut in der Hüft-Endoprothetik--Wie gross ist der Nutzen wirklich?

AIM: Are autologous blood transfusions sufficient or do we need the transfusion of unwashed or washed wound drainage blood in total hip arthroplasty? METHOD: 253 patients undergoing total hip arthroplasty were retrospectively randomized to autologous blood transfusion or transfusion of unwashed wound drainage. We compared the haemoglobin and haematocrit levels as well as the rate of complications. RESULTS: Postoperative blood salvage and reinfusion after total hip joint arthroplasty didn't show any advantages. In 10 % we saw complications after transfusion of unwashed wound drainage. CONCLUSION: We do not recommend the transfusion of wound drainage.

[Expression analysis of different collagens and cytokines in cartilage cells derived from arthrotic hip and knee joints]. / Expressionsanalyse verschiedener Kollagene und Zytokine in Knorpelzellen aus arthrotisch veränderten Hüft- und Kniegelenken.

AIM: Osteoarthritis (OA) is characterized by an irreversible destruction of articular cartilage. This is associated with a multiplicity of factors, causing an increased catabolic metabolism in cartilage. However, the prevalence of the OA is very variable in different joints. Therefore , we conducted a comparative analysis of chondrocytes derived from knee and hip joints with respect to their expression of inflammatory factors, such as IL-1beta, IL-1beta-receptorantagonist, iNOS, components of cartilage matrix (collagen I, II, and VI) as well as vimentin. METHODS: Different cytokines and proteins were detected by immune-histochemical staining of cartilage samples ex vivo. Further, chondrocytes were isolated from OA knee and hip joints, expanded in vitro and gene expression patterns were investigated by quantitative RT-PCR. RESULTS: Chondrocytes from knee and hip joints of OA patients express collagenes I, II and VI, IL-1beta and IL-1beta-RA, iNOS as well as Vimentin. A significant difference in gene expression patterns was not found in chondrocytes from the hip joints versus the knee joint ex vivo or in primary culture cells in vitro. However, in vitro the expression of type I collagen exceeded the expression of type II collagen. The IL-1beta-expression was high ex vivo, remained low during primary culture but was significantly elevated after primary culture in hip chondrocytes. CONCLUSION: Osteoarthritic gene expression patterns in cells derived from hip or knee joints ex vivo and in primary culture were not significantly different. We conclude that the rather frequent occurrence of OA in these joints in comparison to the ankle joint may be associated with a close physiological relation of cells in these joints. However, future studies which will include ankle cartilage must be investigated in further detail.

[Pigmented villonodular synovitis]. / Seltene Schleimhauterkrankung zerstört die Gelenke. Frühzeitige Diagnose erspart Gelenkersatz.

Pigmented villonodular synovitis (PVNS) is a rare, strongly proliferative disease of the lining of thejoint, synovial bursa and tendon (synovial) sheath. If left untreated, it leads to severe destruction of the joint resulting in an early need for endoprosthetic replacement. The clinical signs are unspecific. Using the diagnostic gold standard MRI, the complete extent of PVNS can usually be determined non-invasively. Once histological confirmation has been obtained, radical tumor resection, synovectomy, possibly curettage, and postoperative irradiation must be applied.

[Arthrodesis of the first metatarsophalangeal joint]. / Arthrodese des MTP-I-Gelenks.

Arthrodesis of the first metatarsophalangeal joint is a useful technique for the surgical treatment of hallux rigidus, complicated hallux valgus and rheumatoid forefoot deformity, and for revisions following resection arthroplasty or explantation of a prosthesis combined with interposition of a tricortical bone graft. In primary operations, good or excellent results can be achieved in 80-90% of patients. The articular surface and any exostoses or osteophytes are first resected aiming for a 15-30 degrees extension of the metatarsophalangeal angle and a 5-15 degrees valgus angle. Pseudarthroses occur in 10-13% of arthrodeses stabilized with screws or k-wires. When using a plate for fixation, the rate of pseudarthroses is below 6%. Only a small number of pseudarthroses require revision surgery. Up to 15% of patients develop mostly asymptomatic degeneration of the interphalangeal joint of the hallux.