[Osteomalacia and vitamin D deficiency]. / Osteomalazie und Vitamin-D-Hypovitaminose.

BACKGROUND: Vitamin D and calcium deficiency has a higher incidence in the orthopedic-trauma surgery patient population than generally supposed. In the long term this can result in osteomalacia, a form of altered bone mineralization in adults, in which the cartilaginous, non-calcified osteoid does not mature to hard bone. AIM: The current value of vitamin D and its importance for bones and other body cells are demonstrated. RESULTS: The causes of vitamin D deficiency are insufficient sunlight exposure, a lack of vitamin D3 and calcium, malabsorption, and rare alterations of VDR signaling and phosphate metabolism. The main symptoms are bone pain, fatigue fractures, muscular cramps, muscle pain, and gait disorders, with an increased incidence of falls in the elderly. Osteopathies induced by pharmaceuticals, tumors, rheumatism or osteoporosis have to be considered as the main differential diagnoses. CONCLUSIONS: In addition to the recording of symptoms and medical imaging, the diagnosis of osteomalacia should be ensured by laboratory parameters. Adequate treatment consists of the high-dose intake of vitamin D3 and the replacement of phosphate if deficient. Vitamin D is one of the important hormone-like vitamins and is required in all human cells. Deficiency of vitamin D has far-reaching consequences not only for bone, but also for other organ systems.

Proposal for a histopathological consensus classification of the periprosthetic interface membrane.

AIMS: The introduction of clearly defined histopathological criteria for a standardised evaluation of the periprosthetic membrane, which can appear in cases of total joint arthroplasty revision surgery. METHODS: Based on histomorphological criteria, four types of periprosthetic membrane were defined: wear particle induced type (detection of foreign body particles; macrophages and multinucleated giant cells occupy at least 20% of the area; type I); infectious type (granulation tissue with neutrophilic granulocytes, plasma cells and few, if any, wear particles; type II); combined type (aspects of type I and type II occur simultaneously; type III); and indeterminate type (neither criteria for type I nor type II are fulfilled; type IV). The periprosthetic membranes of 370 patients (217 women, 153 men; mean age 67.6 years, mean period until revision surgery 7.4 years) were analysed according to the defined criteria. RESULTS: Frequency of histopathological membrane types was: type I 54.3%, type II 19.7%, type III 5.4%, type IV 15.4%, and not assessable 5.1%. The mean period between primary arthroplasty and revision surgery was 10.1 years for type I, 3.2 years for type II, 4.5 years for type III and 5.4 years for type IV. The correlation between histopathological and microbiological diagnosis was high (89.7%), and the inter-observer reproducibility sufficient (85%). CONCLUSION: The classification proposed enables standardised typing of periprosthetic membranes and may serve as a tool for further research on the pathogenesis of the loosening of total joint replacement. The study highlights the importance of non-infectious, non-particle induced loosening of prosthetic devices in orthopaedic surgery (membrane type IV), which was observed in 15.4% of patients.

[Anomalous course and anomalous division of the median nerve in the distal forearm]. / Ungewöhnlicher Verlauf und ungewöhnliche Teilung des N. medianus am distalen Unterarm.

An anatomic variation of the median nerve is demonstrated in a female patient suffering from carpal tunnel syndrome subsequent to a distal radius fracture with malalignment and reflex sympathetic dystrophy. The median nerve coursed anterior to the superficial flexor tendons from proximal ulnar toward the distal radial region of the distal forearm, giving off an ulnar branch just 2.5 cm proximal to the flexor retinaculum. This case proves that in the distal forearm, branches of the median nerve can be found both radial and ulnar to the midline.

[Standardized testing of bone implant surfaces with an osteoblast cell culture cyste. III. PVD hard coatings and Ti6Al4V]. / Standardisierte Testung von Skelett-Implantatoberflächen mit einem Osteoblasten-Zellkultursystem. III. PVD-Hartstoffbeschichtungen und Ti6Al4V.

The effect of titanium-based PVD coatings and a titanium alloy on the proliferation and differentiation of osteoblasts was investigated using a standardised cell culture system. Human fetal osteoblasts (hFOB 1.19) were cultured on titanium-niobium-nitride ([Ti,Nb]N), titanium-niobium-oxy-nitride coatings ([Ti,Nb]ON) and titanium-aluminium-vanadium alloy (Ti6Al4V) for 17 days. Cell culture polystyrene (PS) was used as reference. For the assessment of proliferation, the numbers and viability of the cells were determined, while alkaline phosphatase activity, collagen I and osteocalcin synthesis served as differentiation parameters. On the basis of the cell culture experiments, a cytotoxic effect of the materials can be excluded. In comparison with the other test surfaces, [Ti,Nb]N showed greater cell proliferation. The [Ti,Nb]N coating was associated with the highest level of osteocalcin production, while all other differentiation parameters were identical on all three surfaces. The test system described reveals the influence of PVD coatings on the osteoblast differentiation cycle. The higher oxygen content of the [Ti,Nb]ON surface does not appear to have any positive impact on cell proliferation. The excellent biocompatibility of the PVD coatings is confirmed by in vivo findings. The possible use of these materials in the fields of osteosynthesis and articular surfaces is still under discussion.

[TNF-alpha secretion by human macrophage-like cells in response to wear particles and its modification by drugs]. / TNF alpha-Sekretion durch Abriebpartikel im humanen Makrophagenmodell und deren Modulation durch Medikamente.

UNLABELLED: Tumour necrosis factor (TNF) is considered to be the initiator protein of particle disease leading to aseptic loosening of endoprostheses. The aim of the present study was to investigate the TNF response of the macrophage-like cells (MLC) to the periprosthetic particles typically found during revision surgery. For this purpose, particles of polyethylene (PE), pure titanium (Ti), chromium (Cr), cobalt (Co), alumina ceramic (Al2O3) and zirconium dioxide (ZrO2) were used. Additionally, the therapeutic effect of non-steroidal and steroidal drugs, biphosphonates and pentoxyfylline on PE particles was investigated with the aim of differentiating drugs with, from those without, a positive effect on aseptic loosening. METHOD: In an established macrophage model (Rader et al. 1999), THP1 cells (human monocytic cell line) were differentiated over a period of five days in the presence of vitamin D3 and GM-CSF in macrophage-like cells (MLC). To obtain a TNF profile of the different materials, 10(6) MLC were incubated with each of a range of different particle concentrations. For drug testing purposes 80 x 10(8) PE particles, which evoked a maximum TNF response, were applied together with increasing drug concentrations in the same manner. The supernatant was then investigated for TNF secretion using ELISA. RESULTS: It was found that the greatest TNF response was provoked by Co and PE particles, and was 25 and 23 times as high, respectively, in comparison with control. The smallest TNF secretion was seen with Al2O3 (4 x control) and ZrO2 (5 x control). At the recommended dose, non-steroidal anti-inflammatory drugs (NSAIDs) produced no decrease in TNF secretion. The biphosphonates, etidronate and ibendronate significantly reduced the TNF response of the PE-stimulated macrophages (by 1/7 and 1/5, respectively). Therapeutic doses of pentoxyfylline also led to a decrease of 1/5 in maximum TNF release. CONCLUSION: Ceramic articulating surfaces are superior to metal/metal or PE/PE matings in terms of the biological effects of their wear particles. At therapeutic doses, NSAIDs have no beneficial effect on the process of aseptic loosening. Certain biphosphonates and pentoxyfylline have a positive effect on aseptic loosening.

[Cytotoxicity study of high gold content Degutan surfaces of various degrees of roughness with fibroblasts (BALB 3T3) and osteoblasts (hFOB 1.19)]. / Zytotoxizitätsuntersuchung von hochgoldhaltigen Degutan-Oberflächen unterschiedlicher Rauhigkeit mit Fibroblasten (BALB 3T3) und Osteoblasten (hFOB 1.19).

The cytotoxicity of Degutan surfaces with different degrees of roughness, and the effect of surface structures on osteoblast proliferation and differentiation, was investigated with standardised cell culture systems. Fibroblast cell lines (BALB/3T3) and osteoblast cell lines (hFOB 1.19) were used. The number and variability of the cells were determined for assessment of proliferation and alkaline phosphatase activity, collagen I and osteocalcin production were used as parameters for differentiation. In the early phase, the largest numbers of cells and greatest proliferation were measured on polished Degutan surfaces. In the late phase, however, larger numbers of cells and a greater degree of proliferation were to be seen on sandblasted and sandblasted/heat-treated Degutan surfaces. No differences were found for collagen I, osteocalcin production or alkaline phosphatase activity. Neither the osteoblasts nor the fibroblasts revealed a toxic effect of Degutan. The results for osteoblast differentiation correlate with recent studies on identical structured titanium surfaces. In view of the immeasurable amount of ion release, Degutan may be considered an ideal model for an inert material surface.

[Standardized testing of bone implant surfaces with an osteoblast cell culture system. II. Titanium surfaces of different degrees of roughness]. / Standardisiertes Testen von Skelett-Implantatoberflächen mit einem Osteoblasten-Zellkultursystem. II. Titanoberflächen unterschiedlicher Rauhigkeit.

The effect of titanium surfaces with different degrees of roughness on osteoblast proliferation and differentiation was investigated using a standardised cell culture system. Human foetal osteoblasts (hFOB 1.19) were cultured on polished (Ti pol), sandblasted (Ti sb) and sandblasted/heat treated (Ti sb-ht) titanium surfaces for 17 days. Cell culture quality polystyrene (Ps) was used as a control. Cell number and viability were determined for assessment of proliferation. Alkaline phosphatase activity, collagen I and osteocalcin production were measured as parameters for osteoblast differentiation. In the early phase, higher proliferation values were measured on Ti pol. However, on Ti sb and Ti sb-ht higher proliferation was found in the late phase. The activity of the early differentiation marker alkaline phosphatase was higher on Ti pol. No differences were seen for the late differentiation parameters collagen I and osteocalcin. The test system permits the influence of the surface structure on the dynamics of the osteoblast development cycle to be determined. The larger surface area of rough materials leads to an initially delayed, but then prolonged cell proliferation. This model correlates with recent in vivo findings, and confirms the use of rough surfaces for implants in direct contact with bone, even at the cellular level.

[Standardized tests of bone implant surfaces with an osteoblast cell culture system. I. Orthopedic standard materials]. / Standardisiertes Testen von Skelett-Implantatoberflächen mit einem Osteoblasten-Zellkultursystem. I. Orthopädische Standardmaterialien.

The effect of standard orthopaedic materials on proliferation and differentiation of osteoblasts was examined using a standardised cell culture system. Osteoblasts hFOB 1.19 were cultured on stainless steel (SS), a chromium-cobalt-molybdenum alloy (CrCoMb) and commercially pure titanium (cpTi) for 12 days. Cell culture polystyrene (PS) was used as a reference. Cell numbers and cell viability were used as parameters of proliferation. Cell differentiation was assessed using alkaline phosphatase activity, collagen I and osteocalcin production. The parameters of proliferation showed earlier maximum values on PS and cpTi, while proliferation was delayed on SS and CrCoMb. The highest values of differentiation were found on cpTi. The development of alkaline phosphatase activity showed two peaks reflecting apoptosis and redifferentiation. The cell culture system hFOB 1.19 is thus suitable for revealing differences in proliferation and differentiation of osteoblasts on standard orthopaedic materials. The results correlate with previous in vivo findings. Using this system, the dynamic effect of the material surface on the differentiation process of osteoblasts can be demonstrated.

[Transient osteoporosis and osteonecrosis of the femoral head. Risk factors, classification and differential diagnosis]. / Transiente Osteoporose und aseptische Femurkopfnekrose. Risikofaktoren, Klassifikation, Differentialdiagnose.

Osteonecrosis of the femoral head usually affects patients in their third to fifth decade of life. Common risk factors are alcohol, nicotine, corticosteroids, hyperlipidaemia and hypercoagulability. Depending on the stage of the osteonecrosis, the diagnosis is confirmed by radiographs, magnetic resonance imaging or scintigraphy. The ARCO classification (Association Research Circulation Osseous), which is based on older classifications recommended by Ficat/Arlet, Steinberg, Koo or Marcus/Enneking, is a valuable prognostic tool for finding an adequate treatment option. Transient osteoporosis of the hip is controversially discussed as a pre-stage of osteonecrosis or a self-limiting condition based on reflex dystrophy. Conservative and operative treatment options are reported in the literature. Recently published data favour core decompression as an effective procedure for early stage osteonecrosis and transient osteoporosis.

[Standards and perspectives for thromboembolism prophylaxis]. / Standards und Perspektiven der Thromboseprophylaxe.

Thromboembolic complications are one of the most severe complications after orthopaedic or trauma surgery. More than 50% of patients undergoing total knee replacement are at risk of suffering deep-vein thrombosis if not provided sufficient prophylaxis. The former standard prophylaxis with unfractionated heparin has been changed over the few last years to low molecular weight heparin or heparinoids, due to the increased incidence of heparin-induced thrombocytopenia under therapy with unfractionated heparin. Risk management is based on different risk levels: highest risk, high risk, intermediate risk and low risk. The probabilities of suffering from deep-vein thrombosis have been determined dependent on the risk level. In patients with total knee replacement, which are at highest risk, a higher dose for the prevention of thromboembolism has been recommended. The synthetic, selective antithrombin-binding pentasaccharide fondaparinux has been successfully used in prophylaxis for the prevention of thrombosis in highest risk patients. However, because of a higher risk of bleeding, this pentasaccharide can be only given 6-8 h after surgery. Low molecular weight heparins and the pentasaccharide are the standard pharmacological prophylaxis for the prevention of venous thromboembolism. Physical therapy, pneumatic compression, A-V impulse systems, passive ankle motion systems and graduated compression stockings are an additional, effective prophylaxis without side effects.

[Surgical treatment of dislocated 3 and 4-segment fractures of the proximal humerus]. / Die operative Behandlung dislozierter 3- und 4-Segment-Frakturen des proximalen Humerus.

Twenty-eight three- and four-segment fractures of the proximal humerus were treated by plate fixation (n = 22), screw or Kirschner wire stabilization (n = 5), and primary endoprothesis (n = 1). There were no early postoperative complications. Fourteen months after the operation, 80% of the patients examined showed good results; 4 cases had poor results. In comparison to other reports our results are positive and support plate fixation as the method of choice in these situations.

Results of total knee arthroplasty with a metal-backed patellar component. A 6-year follow-up study.

This study reviews the clinical outcome of knee arthroplasty (Microloc, Johnson & Johnson Orthopedics, Norderstedt, Germany) with a resurfacing metal-backed patellar component. Thirty patients were available for clinical and radiographic reexamination with follow-up periods of 36 and 72 months. There were 21 women and 9 men, with an average age of 71.1 years. At the follow-up examination, seven patients demonstrated a metallic friction noise, and three had only mild crepitation at the patellofemoral joint level. In the group complaining of knee pain, the average knee score dropped from 76.9 +/- 9.9 at 36 months to 44.7 +/- 15.3 (P < .05) prior to revision surgery on average at 66 months. The function score dropped during the same time from 72.0 +/- 19.7 to 53.5 +/- 14.9. In contrast, the pain-free group did not demonstrate any significant changes in either knee or function score. Radiographic evaluation showed a patellar tilt of 8.1 degrees +/- 4.0 degrees in the group complaining of pain, compared with 2.5 degrees +/- 2.3 degrees in the pain-free patient collective. All 10 patients complaining of pain and increasing disability underwent revision surgery. At the time of surgery, an obvious polyethylene particle-induced synovitis was found, and in 7 patients it was associated with a metallosis. One of the main reasons for failure of metal-backed polyethylene components is thought to be the undue high stresses forced onto the insert. High loading of only a small fraction of the surface will lead to increased polyethylene creep and particle formation, resulting in synovitis and finally metallosis. Early revision seems to be the best solution to prevent progressive destruction of the entire joint. Previously reported results on metal-backed patellar components show a failure rate of 8.4% after 12 to 24 months. In this study, this rate had already increased to 33.3% after 6 years. One might therefore speculate that at 10 years, revision surgery might become necessary in more than 50% of the surviving patients with this type of implant.

[Pigmented villonodular synovitis of the knee joint--long-term follow-up and therapeutic concept]. / Die pigmentierte villonoduläre Synovialitis am Kniegelenk--Langzeitergebnisse und Therapiekonzept.

Because of pigmented villonodular synovitis (PVS) 17 of 14,500 knee operations were accomplished at our institute between 1975 and 1993. Diffuse PVS (DPVS) was observed in 7 patients, local PVS (LPVS) in 9 patients; in 1 case LPVS was diagnosed on both joints. 15 knees could be examined 4.8 years after first surgery. 3 recurrences (42.9%) were found in the group of DPVS. In the group of LPVS no recurrent tumor growing was observed. It is demonstrated that partial arthroscopic synovectomy is a sufficient therapy in LPVS. The recurrence rate of DPVS ranges from 8 to 50%, the mean recurrence rate described in literature is 31.3%. Neither arthroscopic nor open synovectomy lead to a complete healing of DPVS. Recurrent arthroscopic synovectomy and regular clinical examination using sonography and particular MRI are the best therapeutical concepts in DPVS.

[Diagnosis and therapy of splenic rupture in severe polytrauma]. / Diagnose und Therapie der Milzruptur beim schweren Polytrauma.

In the last 10 years 57 polytraumatized patients were operated on ruptures of the spleen after blunt abdominal trauma. Sonography was used as a reliable method for the decision to an operative treatment. Every spleen that was ruptured grade I and II was primarily preserved by fibrin sealant or together with collagen haemostatic felt. In ruptures of the spleen grade III and IV we preferred the splenectomy. Only in one child with rupture of the spleen grade III preservation of the spleen was achieved by capsular sutures.

[5- to 8-year results of total hip endoprosthesis implantation with the Müller straight shaft prosthesis (cemented TiAlNb shaft)]. / 5-bis 8-Jahres-Ergebnisse nach Hüfttotalendoprothese mit der Müller-Geradschaftprothese (zementierter TiAlNb-Schaft).

The aim of this study was to obtain mid-term results after total hip arthroplasty (THA) with cemented titanium stems. In all, 184 patients with a total of 202 THAs (cemented titanium stem) were clinically and radiologically examined after an average follow-up of 6 years (5-8). The recruitment was 86%. The Harris score was determined clinically. Radiologically, the directly postoperative radiographs were compared to the control radiographs according to the recommendations of Gruen et al. and Johnston et al. In 2 cases (1%) septical complications appeared after 2 years, which were treated in two-stage surgery. To date, revisions after loosening have been carried out in 3 cases (1.5%). This is equivalent to a revision rate of 2.5%. Three further cases showed evidence of loosening in more than 5 radiolucent lines (RLL), according to Gruen, making close-meshed controls necessary. Clinically, in all of the 6 cases of aseptic loosening, the Harris score remained above 80 points. In 36 cases, more than one RLL, compared to the postoperative radiographs, was ascertained and mainly found in zones 1, 7, 8, and 14. Substantial subsidence or varus could only be observed in one case. The clinical results in the Harris score were good or excellent in 78% and satisfactory in 20%. With an average of 75 at the time of follow-up, the age of the patients was, according to the indication that only patients above age 60 are to receive cemented-stem prostheses, clearly advanced. The body weight was significantly higher (82 kg; d = 2.4) in those 6 patients having evident RLL, than in patients without RLL. The ratio body weight to surface of the stem was especially different (1.5 kg/cm2 versus 1 kg/cm2; P < 0.005) in the two groups. This did not apply to sex or activity of the patient, size or kind of stem, Harris score, ectopic ossification, or body weight index. The biggest possible stem should be implanted. Not all cemented titanium stem prostheses are necessarily affected with a high rate of loosening at a mid-term follow-up.

[Comparison between low-molecular and unfractionated heparin in the prevention of thrombosis in patients with total endoprosthetic replacement of hip and knee joint]. / Vergleich zwischen niedermolekularen und unfraktionierten Heparinen (PTT gesteuert) in der Thromboseprophylaxe bei Patienten mit totalendoprothetischem Ersatz von Hüft- und Kniegelenk.

PURPOSE: Thrombosis-prophylaxies with heparins after total hip arthroplasty (THP) and total knee arthroplasty (TKA) is well accepted. The aim of this study was to compare the low molecular weight heparin (Enoxaparin) with PTT adjusted unfractionated heparin (Na-heparin). METHODS: In a prospective study of 226 patients after THA and TKA, we performed physical examination and ultrasound in compression and duplex technique one day before surgery and at the 7th and 14th day after surgery. 120 patients received Enoxaparin 1 x 40 mg per day in fixed dosage. 106 patients received Na-heparin 3 x 5000 IE. Since PTT did not reach 40 seconds, Na-heparin dosage was increased to 3 x 7500 IE. RESULTS: The overall thrombosis rate was 4% (n = 9), in the Enoxaparin group 2.9% for the 70 THA and 10% for the 50 TKA. Thrombosis occurred in the group of unfractionated heparin (PTT adjusted) in 1.8% after THA and in 2% after TKA. In TKA, there is statistical difference between the two heparin groups. CONCLUSION: In the thrombosis prophylaxis of TKA, PTT adjusted unfractionated heparin is superior to low molecular weight heparin in fixed dosage.

Heterotopic ossification after total knee arthroplasty. 54/615 cases after 1-6 years' follow-up.

We found heterotopic ossifications in 54 (9%) of 615 cases after total knee arthroplasty. The largest ossifications were located in the anterior distal femur. In 12 cases smaller ossifications were found in other knee regions. The development of heterotopic ossification showed a positive correlation with hypertrophic arthrosis and a negative correlation with rheumatoid arthritis. We propose a new 3-grade classification which refers only to the anterior distal femoral region. Grade III heterotopic ossifications occurred in 4 patients (4 knees) who had clinical symptoms; 2 were successfully reoperated with removal of the ossifications. Prophylaxis should be considered in patients with marked hypertrophic arthrosis or marked periosteal damage to the anterior distal femur.

Low-molecular-weight heparin and partial thromboplastin time-adjusted unfractionated heparin in thromboprophylaxis after total knee and total hip arthroplasty.

Thromboprophylaxis with heparins after total hip arthroplasty (THA) and total knee arthroplasty (TKA) is well established. The aim of this study was to compare low-molecular-weight heparin (enoxaparin) with partial thromboplastin time (PTT)-adjusted, unfractionated heparin (heparin sodium). In a prospective study of THA and TKA 246 patients, physical examination and compression and duplex ultrasound were performed 1 day before and 7 and 14 days after surgery. One hundred thirty patients received 40 mg enoxaparin subcutaneously once per day. One hundred sixteen patients received 5,000 IU heparin sodium subcutaneously 3 times daily. As the PTT did not reach 40 seconds, the heparin sodium dosage was increased to 7,500 IU 3 times daily. The overall thrombosis rate was 4% (n = 10). In the enoxaparin group, the rate was 2.9% of the 70 THAs and 10% of the 60 TKAs. Thrombosis also occurred in the group that received heparin sodium: 1.8% of the THAs and 1.7% of the TKAs. For TKA, the difference between the 2 heparin groups was statistically significant. In the thromboprophylaxis of TKA, PTT-adjusted unfractionated heparins are superior to fixed doses of low-molecular-weight heparins.

[Possibilities for interpreting digital migration analysis of cement-free PM total hip endoprostheses]. / Interpretationsmöglichkeiten der digitalen Wanderungsanalyse zementfreier PM-Hüfttotalendoprothesen.

PURPOSE: Aim of this study was the validation of a digital measurement device for hip implants. METHODS: From 43 patients with a minimum of four subsequent roentgenograms 246 roentgenograms of PM-shafts (an average 5.72/shaft) and 142 roentgenograms of PM-cups (an average 6.45/cup) were digitized on a DiagnostiX 2048 basis station (Pace Systems, Germany). Modified Sutherland/Nunn methods were chosen for measuring purposes. Regression analysis was done and the results were correlated to implant loosening. RESULTS: Concerning the total vertical migration of the cup there is a significant (p < 0.04) difference between the loosened components (6.02 +/- 2.59 mm) and the fixed cups (2.26 +/- 2.89 mm). The average annual vertical migration rate of the stem shows a highly significant difference (p < 0.007) when comparing loosened stems (0.82 +/- 0.43 mm, total migration 4.78 +/- 2.89 mm) and fixed ones (0.20 +/- 0.54 mm, total migration 1.72 +/- 3.02 mm) CONCLUSIONS: Using the regression analysis and a sufficient number of pictures the system allows us to give migration values that make loosening likely. However for the single implant an individual prognosis of loosening is not possible.