Ligament graft fixation with bioabsorbable interference screws is a standard procedure in cruciate ligament replacement. Previous screw designs may resorb incompletely, and can cause osteolysis and sterile cysts despite being implanted for several years. The aim of this study was to examine the in vivo degradation and biocompatibility of the new Milagro interference screw (Mitek, Norderstedt, Germany). The Milagro interference screw is made of 30% ss-TCP (TriCalcium phosphate) and 70% PLGA (Poly-lactic-co-glycolic acid). In the period between June 2005 and February 2006, 38 patients underwent graft fixation with Milagro screws in our hospital. Arthroscopic ACL reconstruction was performed using hamstring tendon grafts in all the patients. MR imaging was performed on 12 randomly selected patients out of the total of 38 at 3, 6 and 12 months after surgery. During the examination, the volume loss of the screw, tunnel enlargement, presence of osteolysis, fluid lines, edema and postoperative screw replacement by bone tissue were evaluated. There was no edema or signs of inflammation around the bone tunnels. At 3, 6 and 12 months, the tibial screws showed an average volume loss of 0, 8.1% (+/-7.9%) and 82.6% (+/-17.2%, P < 0.05), respectively. The femoral screws showed volume losses of 2.5% (+/-2.1%), 31.3% (+/-21.6%) and 92.02% (+/-6.3%, P < 0.05), respectively. The femoral tunnel enlargement was 47.4% (+/-43.8%) of the original bone tunnel volume after 12 months, and the mean tunnel volume of the tibial tunnel was -9.5% (+/-58.1%) compared to the original tunnel. Bone ingrowth was observed in all the patients. In conclusion, the resorption behaviour of the Milagro screw is closely linked to the graft healing process. The screws were rapidly resorbed after 6 months and, at 12 months, only the screw remnants were detectable. Moreover, the Milagro screw is biocompatible and osteoconductive, promoting bone ingrowth during resorption. Tunnel enlargement is not prevented in the first months but is reduced by bone ingrowth after 12 months.

OBJECTIVE AND METHODS:The treatment of the acromioclavicular joint dislocation is a topic of constant debate. Objective of the study was to analyze if operative treatment of Rockwood types 3 and 5 acromioclavicular joint dislocations is superior to nonoperative treatment. Treatment outcomes of 100 patients (91 male, 9 female, median age 33.7 +/- 8.6) from 4 different hospitals/departments of trauma surgery were analyzed. Clinicofunctional, radiological, as well as subjective parameters were taken into consideration.RESULTS:Clinicofunctional outcome of the operative treatment of acromioclavicular joint dislocation was very good in 91.2 % of patients. 87.7 % of the operated patients had a subjectively stable joint. The patients operated on for the acromioclavicular joint dislocation were capable of exercising after 13 weeks post surgery. versus 25.3 weeks in nonoperatively treated patients. The operated patients had a Rowe score and Constant score as high as 90.7 and 91.8 respectively, reflecting an excellent treatment outcome.CONCLUSION:Operative anatomic reconstruction of the injured acromioclavicular joint leads to very good clinicofunctional outcomes. The operative technique plays only a minor role in achieving these outcomes. The rate of complications is low for all operative techniques listed here. Demanding patients and multimedia education of patients are the reasons for a majority of operated patients in this study (97 %).

Total meniscus resection usually leads to osteoarthritis of the knee joint. Preservation and refixation of the injured menisci are therefore of great clinical importance.

Aim of the study was to analyse the results following osteosynthesis of proximal humerus fractures with cannulated blade plate 90degrees (Synthes, Mathys Medizinaltechnik AG, Bettlach, Schweiz) in elderly patients. Between 6/1998 and 12/1999 we treated 20 patients (12 female, 8 male) > 65 years (65-92 y, O75 y) with the cannulated blade plate (fracture type according to AO: 8 x 11-A3, 5 x 11-B1, 3 x 11-B2, 1 x 11-B3 und 3 x 11-C2). Regarding to mechanical and functional advantages we modified the 90degrees angulation of the implant by bending intraoperatively up to 110-120degrees. Early post-op physiotherapy was permitted. The radiological results of all patients were evaluated and in 13 patients a clinical follow-up (median 8 months) was obtained. According to the Constant-score 62 points on average were achieved, which corresponds to a satisfactory result (contralateral shoulder 92 points). Complications due to the implant were loosening of the blade plate in 3 cases (A3, B2, C2) and 1 perforation of the blade plate (Q). The consecutive reoperation consisted in a compound osteosynthesis with the blade plate (A3, 132) in 2 cases, a prosthetic replacement and a removal of the implant (C2) in 1 case respectively. Neither infection, major nerve and vessel trauma nor avascular necrosis occurred. The cannulated blade plate 90degrees represents a justified alternative in the treatment of displaced fractures of the proximal humerus in elderly patients. Commendable indications are fracture types A and B according to AO with stable fixation of the blade plate in the humeral head, which allow early physiotherapy and avoid an alteration of the rotator cuff. C-type fractures tend to complications (2/3).

Aim of the study was to analyse the results following osteosynthesis of proximal humerus fractures with cannulated blade plate 90 degrees (Synthes, Mathys Medizinaltechnik AG, Bettlach, Schweiz) in elderly patients. Between 6/1998 and 12/1999 we treated 20 patients (12 female, 8 male) > 65 years (65-92 y, 75 y) with the cannulated blade plate (fracture type according to AO: 8 x 11-A3, 5 x 11-B1, 3 x 11-B2, 1 x 11-B3 und 3 x 11-C2). Regarding to mechanical and functional advantages we modified the 90 degrees angulation of the implant by bending intraoperatively up to 110-120 degrees. Early post-op physiotherapy was permitted. The radiological results of all patients were evaluated and in 13 patients a clinical follow-up (median 8 months) was obtained. According to the Constant-score 62 points on average were achieved, which corresponds to a satisfactory result (contralateral shoulder 92 points). Complications due to the implant were loosening of the blade plate in 3 cases (A3, B2, C2) and 1 perforation of the blade plate (C2). The consecutive reoperation consisted in a compound osteosynthesis with the blade plate (A3, B2) in 2 cases, a prosthetic replacement and a removal of the implant (C2) in 1 case respectively. Neither infection, major nerve and vessel trauma nor avascular necrosis occurred. The cannulated blade plate 90 degrees represents a justified alternative in the treatment of displaced fractures of the proximal humerus in elderly patients. Commendable indications are fracture types A and B according to AO with stable fixation of the blade plate in the humeral head, which allow early physiotherapy and avoid an alteration of the rotator cuff. C-type fractures tend to complications (2/3).

The principles of treatment for fractures of the femoral shaft in children include conservative and operative management. Traditionally, these fractures have been treated conservatively with skeletal traction. More frequent consideration is being given to the psychological and economical outcome. At what age of the patient surgery can be performed is still open to debate. From 1988 to 1999, 52 children with closed femoral shaft fractures were treated conservatively in the Klinik für Unfallchirurgie, Plastische und Wiederherstellungschirurgie der Universität Göttingen (until 1994 Klinik für Allgemeinchirurgie). Overhead traction was applied in 27 children with a mean age of 19.9 months (group I), and a 90-90 skeletal traction was performed in 25 children with a mean age of 47 months (group II). This treatment was followed by spica casting on an outpatient basis. At a mean follow-up of 6 11/12 years (2 4/12-12 5/12) in 33 children all fractures were healed and no malalignment with clinical relevance could be observed. In four patients the limb overgrowth was 15-20 mm. The assessment of psychological and somatic aspects revealed disturbances in the family environment. The average length of hospitalization was much shorter in group I (mean: 17.4 days) than in group II (mean: 23.7 days). Our study confirms the good long-term results after conservative treatment of femoral shaft fractures in children up to 6 years. Social and psychological problems due to the prolonged period of hospitalization as well as the high costs of skeletal traction favor surgical treatment for children older than 3-4 years.

Die Frage der "kind- und frakturgerechten" Behandlung der isolierten Oberschenkelfraktur im Kindesalter wird insbesondere vor dem Hintergrund minimal-invasiver Operationsverfahren zunehmend kontrovers diskutiert. Lange galt die konservative Behandlung mit Extension als das Verfahren der Wahl. Neben rein physisch definierten Parametern müssen aber auch mögliche psychische und soziale Konsequenzen bedacht werden. Besonders die Frage, ab welchem Lebensalter eine operative Stabilisierung zu bevorzugen ist, bleibt ungeklärt.

Retrospectively 20 patients with a surgically treated ankle fracture caused by hobby-accidents were examined clinically and radiologically by a score modified to Phillips after 12 months postoperatively. Further they have taken part in a dynamical gait analysis at the same time. A group of 20 healthy adults was used as a control group comparable to age, sex, height and weight. Although 19 patients out of 20 have achieved a good result at the score evaluation and none of them was clinically noticed with any pathological gait, gait analysis has shown a significant slowed gait speed and a decreased stride length. The reduction of the plantarflexor moment at the injured ankle joint immediately following heel contact was yet the most remarkable result of the gait analysis. The changes of gait pattern are interpreted as an adapted and internalized motion pattern caused by pain and behaviour of rest at any time while the mobilisation-phase was going on. It could not document any significant correlation between subjective and clinical parameters and parameters registered by gait analysis. However, a significant correlation of gait-analysed parameters was found between the injured and uninjured side. By dynamical gait analysis it is possible to quantify remarkable gait changes, to obtain objective data, but also to demonstrate asymmetrical loading and motion that were not clinically detectable previously. It follows that it can be relevant to patients with complaints by leading them to specific physiotherapeutical treatment and gait training so that they would be able to carry on their sports-activities again.

Zusammenfassung Unter allen Beckenfrakturen, die meistens im Rahmen von Polytraumen vorkommen, sind über traumatische Hemipelvektomien in der Literatur nur vereinzelt Angaben zu finden [10, 11, 13, 14]. Die traumatische Hemipelvektomie ist dabei die Extremform des Beckentraumas und fast immer tödlich. Wenige Patienten überleben im Verlauf dieses massive Trauma. In unserer Klinik wurden in den Jahren 1981 und 1982 2 Patienten mit traumatischer Hemipelvektomie eingeliefert und operativ versorgt [12]. Es ist uns erstmalig möglich einen Patienten 18 Jahre nach einem solchen Trauma zu untersuchen und in Bezug auf seine postoperativen Komplikationen und seine Lebensqualität zu befragen. Anhand der Kasuistik dieser 2 überlebenden Patienten soll über das verheerende Verletzungsmuster, die Therapie und die posttraumatische Lebensqualität berichtet werden. Des Weiteren sollen Perspektiven der modernen Rehabilitation dargestellt werden.

69 patients with kickboard injuries were treated over a 5-month period. 6 patients were admitted to hospital. Fractures (48%), contusions/ lacerations (45%) and capsular/ ligamentuous injuries (27%) were the most prevalent types of injury. Injuries of the elbow, forearm, wrist and hand accounted for 54% of all cases. Ankle (23%), head (6%) and knee were other regions frequently involved. It is concluded that kickboard-driving imposes a severe risk of injuries. The typical kickboard injuries was the fracture of the wrist and the ankle sprain. Protective equipment for the injured regions is very important to prevant injury.

Kritsche Analyse der Ergebnisse der mit der durchbohrten Winkelplatte versorgten proximalen Humerusfraktur im hohen Lebensalter. Methode: Von 6/98-12/99 wurden prospektiv 20 Patienten (12 w, 8 m) >65 Jahre (65–92 J., × 75 J.) versorgt (A0-Klassi-fikation:8 Ø 11-A3, 5 Ø 11-Bl, 3 Ø 11-B2, l Ø 11-B3 und 3 Ø 11-C3).Post-opfrühfunktionelle Behandlung. Nachuntersuchung mit Constant Score (Ø 9 Monate post-op). Ergebnisse: Komplikationen: 3 Ø Klingenlockerung (A3, B2, C3) und 1 Ø Klingenperforation (C3), jeweils mit Revisionseingriff als 2 Ø Verbundosteosynthese mit der Winkelplatte (A3, B2), 1 Ø Endoprothese (C3), 1 Ø vorzeitige ME (C3). Keine Infektion oder Gefäß-Nervenverletzung, keine Kopf-nekrose. Im Constant Score erreichten 13 Pat. mit × 62 Pkt. (Gegenseite 94 Pkt.) ein befriedigendes Ergebnis. Schlußfolgerung: Gute Indikation: A- und B-Frakturen mit stabiler Verankerung der Klinge, funktioneller Nachbehandlung und Schonung der Rotatorenmanschette. Problematisch sind C-Frakturen, besonders mit kleinem Kalottenfragment (Komplikation bei 2/3).

Phosphate layers formed in a model bath were electrochemically modified with copper and a cataphoretic polymer film. While Cu fills the total pore volume, the deposition of the polymer is, in the initial phase, restricted to the bottom of the pore. This behaviour was used to determine the effective layer thickness and the pore volume. A cone shaped opening of the pores is concluded from transients of copper deposition and in connection with the cataphoretic painting experiments. These results matched the growth mechanism of the phosphate layer suggested in our previous studies.

Equivalent circuits for the phosphate layer were obtained from electrochemical impedance spectra. The dominant time constant is due to the transfer resistance Rt and the double-layer capacitance Cdl. An initial high frequency pseudo-inductive time constant Lpseudo/R2 is followed by a capacitive time constant R2C2 as the phosphating time increases. The results obtained on varying the reference electrode position and the bath composition suggest that Lpseudo/R2 is due to the electrical coupling between cell elements while R2C2 is due to an amorphous precipitation of FePO4 in the pores of the phosphate layer. Since electrochemical impedance spectroscopy is restricted to t > 200 s, ac conductance transients were recorded continuously to determine the coverage. Corrosion potential transients were measured simultaneously. These methods were used to estimate the effect of oxidants on the phosphating kinetics with respect to the coverage. The results obtained by the various methods were compared with ex-situ measurements from a previous study.

An electrochemical short-time test, which is based on potentiodynamic oxide formation on the substrate, was employed to determine the unprotected metal surface of phosphate layers selectively. The decrease of free metal area and, consequently, the increase of coverage during phosphating were followed by potentiodynamic current and capacity measurements. Using a model system consisting of mild steel with various pretreatments and a low zinc immersion phosphating process, fundamental stages of the phosphate layer formation are discussed. The proposed method enables the determination of tnucl and tfinal as important parameters of the phosphating process and the optimal treatment time at (A/A0)min. It is therefore well-suited for the quality control of phosphate coatings.