Mid-term outcome of arthroscopic AMIC for the treatment of articular cartilage defects in the knee joint is equivalent to mini-open procedures.

INTRODUCTION: We present the first retrospective study that compares two various autologous matrix-induced chondrogenesis (AMIC) surgical interventions to repair grade III-IV cartilage defects in the knee. Patients who underwent minimally invasive (arthroscopy) or open (mini-arthrotomy) AMIC were followed up to 2 years to investigate if minimally invasive AMIC is superior to open procedures. MATERIALS AND METHODS: Overall n = 50 patients with focal and contained grade III-IV articular cartilage defects in the knee joint were followed in a consecutive cohort study. 20 patients were treated arthroscopically (female 7, male 13; age: mean 38.2 years, range 18-70 years; BMI: mean 27.0, range 18.7-34.7; defect size: mean 3.1 cm2, range 1.0-6.0 cm2), and 30 patients via mini-arthrotomy (female 13, male 17; age: mean 34.4 years, range 14-53 years, BMI: mean 23.9, range 18.4-28.7; defect size: mean 3.4 cm2, range 1.5-12.0 cm2). The primary defect localization was the medial femoral condyle. RESULTS: AMIC led to a significant improvement of VAS pain, KOOS and Lysholm scoring for up to 2 years compared to pre-op. Outcome analysis revealed no significant differences between the two different surgical approaches. CONCLUSIONS: Our results suggest that mini-open AMIC is equivalent to the arthroscopic procedure. The anticipatory hypothesis that minimally invasive approaches bring greater patient benefit per se could not be confirmed. Therefore, we recommend to perform AMIC where indicated and suggest that the surgeon's personal skills profile guide the choice of surgical approach. LEVEL OF EVIDENCE: III.

In-vitro evaluation of surgical helmet systems for protecting surgeons from droplets generated during orthopaedic procedures.

BACKGROUND: Operating theatres and surgical clothing are designed to protect the patient from surgical site infections. However, there is still a risk of infection of the surgical team with blood-borne pathogens via ocular or mucocutaneous exposure. Whereas conventional surgical clothing provides some protection against contamination, surgical helmet systems (SHS) are intended to provide a high level of protection by forming a barrier for particles, aerosols and fluids between surgeon and surgical field of work. AIM: The aim of this study was to quantify the contamination of the surgeon by droplets during orthopaedic procedures by an in-vitro simulation of hip and knee arthroplasty while wearing SHS versus conventional surgical clothing. METHODS: Hip and knee arthroplasty procedures were performed on artificial foam bone, which was continuously kept wet with a marker fluid. Each of the procedures was carried out by ten subjects wearing conventional surgical clothing or wearing SHS with integrated toga. After the simulated operation, pictures of the subjects were taken under ultraviolet illumination. Images wearing the full gown, and after removal of the gown, were evaluated for stained areas. FINDINGS: The contamination risk was 30% while wearing conventional clothing. In none of the 20 subjects using the SHS stains could staining be detected after removal of the protective clothing. CONCLUSION: This study has demonstrated that the protective properties of the SHS are superior to conventional surgical clothing. Using SHS in high-risk procedures could reduce occupational exposure to blood-borne infections in surgeons.

An electronically instrumented internal fixator for the assessment of bone healing.

OBJECTIVES: The monitoring of fracture healing is a complex process. Typically, successive radiographs are performed and an emerging calcification of the fracture area is evaluated. The aim of this study was to investigate whether different bone healing patterns can be distinguished using a telemetric instrumented femoral internal plate fixator. MATERIALS AND METHODS: An electronic telemetric system was developed to assess bone healing mechanically. The system consists of a telemetry module which is applied to an internal locking plate fixator, an external reader device, a sensor for measuring externally applied load and a laptop computer with processing software. By correlation between externally applied load and load measured in the implant, the elasticity of the osteosynthesis is calculated. The elasticity decreases with ongoing consolidation of a fracture or nonunion and is an appropriate parameter for the course of bone healing. At our centre, clinical application has been performed in 56 patients suffering nonunion or fracture of the femur. RESULTS: A total of 39 cases of clinical application were reviewed for this study. In total, four different types of healing curves were observed: fast healing; slow healing; plateau followed by healing; and non-healing. CONCLUSION: The electronically instrumented internal fixator proved to be valuable for the assessment of bone healing in difficult healing situations. Cost-effective manufacturing is possible because the used electronic components are derived from large-scale production. The incorporation of microelectronics into orthopaedic implants will be an important innovation in future clinical care.Cite this article: B. Kienast, B. Kowald, K. Seide, M. Aljudaibi, M. Faschingbauer, C. Juergens, J. Gille. An electronically instrumented internal fixator for the assessment of bone healing. Bone Joint Res 2016;5:191-197. DOI: 10.1302/2046-3758.55.2000611.

Traumatic Rupture of the Distal Triceps Tendon (A Series of 7 Cases).

Even non-traumatic ruptures of the triceps tendon are rare, surgical therapy should be recommended in all cases, because of poor results after non-operative treatment. A golden standard for the surgical procedure is not established. A small series of traumatic distal tendon ruptures was treated surgical in our hospital and was followed up after 12 months concerning their function. Very good and good results could be found with a strong reintegration of the tendon by using transosseus sutures with non resorbable suture material. The refixation with suture anchors showed disappointing results with early pull-outs of the anchor. Revision with screw augmentation with a washer had to be performed. Concerning the biomechanical forces, which show up on the olecranon (up to 40 NM), the refixation of the triceps tendon has proved to be extremely resistant against pull out forces. The good results by using non absorbable transosseus sutures led to a standardized procedure in our trauma center, even the rupture is not traumatic.

Refixation of osteochondral fractures by ultrasound-activated, resorbable pins: An ovine in vivo study.

OBJECTIVES: Osteochondral injuries, if not treated adequately, often lead to severe osteoarthritis. Possible treatment options include refixation of the fragment or replacement therapies such as Pridie drilling, microfracture or osteochondral grafts, all of which have certain disadvantages. Only refixation of the fragment can produce a smooth and resilient joint surface. The aim of this study was the evaluation of an ultrasound-activated bioresorbable pin for the refixation of osteochondral fragments under physiological conditions. METHODS: In 16 Merino sheep, specific osteochondral fragments of the medial femoral condyle were produced and refixed with one of conventional bioresorbable pins, titanium screws or ultrasound-activated pins. Macro- and microscopic scoring was undertaken after three months. RESULTS: The healing ratio with ultrasound-activated pins was higher than with conventional pins. No negative heat effect on cartilage has been shown. CONCLUSION: As the material is bioresorbable, no further surgery is required to remove the implant. MRI imaging is not compromised, as it is with implanted screws. The use of bioresorbable pins using ultrasound is a promising technology for the refixation of osteochondral fractures.

[Medical appraisal of anterior cruciate ligament ruptures]. / Begutachtung der vorderen Kreuzbandruptur.

BACKGROUND: Anterior cruciate ligament tears are one of the most common human ligament ruptures. The assessment of such ruptures is particularly difficult because most ACL injuries involve minimal to no contact. The steps of the assessment are presented with the necessary requirements. METHOD: Criteria for determining the cause of anterior cruciate ligament ruptures are discussed against the background of our experience and the literature. Different definitions of causality apply to German statutory accident insurance (workers' compensation) on the one hand and to private accident insurance on the other. RESULTS: The assessment of disability within the scope of workers' compensation in most cases results in "under 10 to 30%", while in private accident insurance it is rated as 1/10 to 1/20 degree of disablement.

[Osteoporotic fractures of the distal radius. What is new?]. / Osteoporotische Frakturen des distalen Radius. Was ist neu?

The demographic development will result in an increase of up to 30 % of distal radius fractures. There are various therapy options but what is new? Conservative therapy: conservative therapy is reserved for stable fractures only. Osteosynthesis by K-wires: due to low biomechanical stability in older patients, insufficient functional and radiological results were achieved. External fixator: external fixators are used in compound and complex fractures and show better results than K-wire osteosynthesis. Angular stable plate osteosynthesis: with angular stable plates it is possible to achieve good results with complex fractures and they are currently the method of choice. Intramedullary osteosynthesis: intramedullary nails result in a faster functional improvement than angular stable plates but have limitations. New is that 90% of osteoporotic distal radial fractures are treated with angular stable plates which have shown good results in single study groups.

Mortality in patients with traumatic spinal cord injury: descriptive analysis of 62 deceased subjects.

STUDY DESIGN: Retrospective study. OBJECTIVE: To investigate the causes of death in patients who were ≤ 50 years at the time of traumatic spinal cord injury (tSCI). SETTING: Convenience sample of a tertiary rehabilitation center. METHODS: All deceased patients with tSCI who survived a minimum of 10 years post-injury, were included. In addition, causes of death were compared between subjects surviving <10 years and ≥ 10 years. Neurological assessments were performed according to the American Spinal Injury Association scale. Data on causes of death were analyzed using the ICD-10 classifications. Differences were calculated using the Mann-Whitney and chi-square tests. RESULTS: A total of 100 patients, with 38 and 62 surviving <10 and ≥ 10 years, respectively, were included. No significant differences in causes of death were identified between these two groups. In patients surviving ≥ 10 years, paraplegia was associated with a higher life expectancy compared with tetraplegia, 34 and 25 years (p = 0.008), respectively, and the leading causes of death were septicemia (n = 14), ischemic heart disease (n = 10), neoplasms (n = 9), cerebrovascular diseases (n = 5), and other forms of heart diseases (n = 5). Septicemia, influenza/pneumonia, and suicide were the leading causes of death in tetraplegics, whereas ischemic heart disease, neoplasms, and septicemia were the leading causes of death in paraplegia. CONCLUSION: Our monocentric study showed that in 62 deceased patients with SCI, the leading causes of death were septicemia, cardiovascular diseases, neoplasms, and cerebrovascular diseases. In addition, no significant differences were identified between causes of death among patients surviving <10 years and ≥ 10 years post-injury.

Biomechanical analysis of a synthetic femur spiral fracture model: Influence of different materials on the stiffness in flexible intramedullary nailing.

BACKGROUND: Flexible intramedullary nail fixation of dislocated diaphyseal femur fractures has gained wide acceptance for children and adolescents with open physes. Studies with a special emphasis on complications reveal frequent problems regarding stability, usually in complex fracture types such as spiral fractures and in older children weighing >40kg. This biomechanical study analyses how much the material of the nails influences the stiffness in a synthetic bone model. METHODS: Twenty-four composite grafts (Sawbones®, 4th generation, medullar canal of 10mm) with an identical spiral fracture were used in three configurations of eight grafts. Elastic stable intramedullary nailing was performed in a retrograde C-shaped manner with two nails of equal size (2×3.5mm). Close contact of the fragments could be achieved. We compared Group A (steel nails) with Group B and C (two types of titanium nails). All specimens underwent 4-point bending, torsion and axial compression in the 0° and 9° positions, and the results were analysed. FINDINGS: Group A (steel nails) revealed a significantly higher stiffness in all directions than Group B. Apart from compression in the 9° position this steel nail fixation showed significant higher stiffness than titanium nails of Group C. Comparing Group B and C did not show an systematic difference. INTERPRETATION: In this biomechanical study with composite artificial bones the use of steel Nails demonstrated the highest stiffness in our model when compared to two different titanium nail configurations. Apart from in cases of known allergy or planned MRI-examinations our results and data from the literature question the use of titanium nails.

How does knowledge about spinal cord injury-related complications develop in subjects with spinal cord injury? A descriptive analysis in 214 patients.

STUDY DESIGN: Monocentric cohort study. OBJECTIVE: To investigate the acquisition of knowledge about spinal cord injury (SCI)-related complications in SCI patients. SETTING: Level 1 trauma center. METHODS: All patients with a traumatic or non-traumatic SCI were included in the study. Data were collected at admission, post-admission at 1 and 3 months and post-discharge at 6, 18 and 30 months. The discharge of all patients was between 3 and 6 months post-admission. Knowledge about pressure ulcers and bladder management was tested using the 'Knowledge' score. This score has a minimum and maximum of 0 and 20 points. To detect differences across the multiple time intervals, the Friedman test was used. Differences in the number of patients with poor (0-8), average (9-12) and good knowledge (13-20) between the different age classifications (age at injury) were calculated using a χ (2)-test. RESULTS: A total of 214 patients were included. At discharge subjects had increased their knowledge score to 11.2 compared with 5.4 on admission (P < 0.001). After 30 months, however, the mean score decreased to 10.8 points. At the time of discharge, the number of patients who achieved poor, average or good knowledge were 48 (22.4%), 65 (30.4%) and 101 (47.2%), respectively. Subjects of ∼50 years old and tetraplegics had better (P < 0.001) knowledge compared with subjects of ∼50 years old and paraplegics, respectively. CONCLUSION: In this study, less than 50% of SCI patients had good knowledge about bladder management and pressure ulcers after being discharged.

Biopolymer augmentation of the lag screw in the treatment of femoral neck fractures--a biomechanical in-vitro study.

The cut-out of the sliding screw is one of the most common complications in the treatment of intertrochanteric fractures. The reasons for the cut-out are: a suboptimal position of the hip-screw in the femoral head, the type of fracture and poor bone quality. The aim of this study was to reproduce the cut-out event biomechanically and to evaluate the possible prevention of this event by the use of a biopolymer augmentation of the hip screw. Concerning the density and compression force of osteoporotic femoral bone polyurethane foam according to the terms of the Association for Standard Testing Material (ASTMF 1839-97) was used as test material. The polyurethane foam Lumoltan 200 with a compression force of 3.3 Mpa and a density of 0.192 g/cm(3) was used to reproduce the osteoporotic bone of the femoral fragment (density 12 lbm/ft(3)). A cylinder of 50 mm of length and 50 mm of width was produced by a rotary splint raising procedure with planar contact. The axial load of the system was performed by a hydraulic force cylinder of a universal test machine type Zwick 1455, Ulm, Germany. The CCD-angle of the used TGN-System was preset at 130 degrees. The migration pattern of the hip screw in the polyurethane foam was measured and expressed as a curve of the distance in millimeter (mm) against the applied load in Newton (N) up to the cut-out point. During the tests the implants reached a critical changing point from stable to unstable with an increased load progression of steps of 50 Newton. This unstable point was characterized by an increased migration speed in millimeters and higher descending gradient in the migration curve. This peak of the migration curve served as an indicator for the change of the hip screw position in the simulated bone material. The applied load in the non-augmented implant showed that in this group for a density degree of 12 (0,192 g/cm(3)) the mean force at the failure point was 1431 Newton (+/- 52 Newton). In the augmented implant we found that the mean force at the failure point was 1987 Newton (+/- 84 Newton). This difference was statistically significant. In conclusion, the bone density is a significant factor for the stability of the hip screw implant. The osteosynthesis with screws in material with low density increases the chance for cut-out. A biopolymer augmented hip screw could significantly improve the stability of the fixation. The use of augmentation with a fast hardening bone replacement material containing polymer-ceramic changes the point of failure under axial load in the osteoporotic bone model and could significantly improve the failure point. Our study results indicate, that a decrease of failure in terms of cut-out can be achieved with polymer augmentation of hip screws in osteoporotic bones.

Early Weight Bearing of Calcaneal Fractures Treated by Intraoperative 3D-Fluoroscopy and Locked-Screw Plate Fixation.

Operative therapy of intraarticular fractures of the calcaneus is an established surgical standard. The aim is an accurate reduction of the fracture with reconstruction of Boehler's angle, length, axis and subtalar joint surface. Intraoperative 3D-fluoroscopy with the Siremobil Iso-C 3D(R) mobile C-arm system is a valuable assistant for accurate reconstruction of these anatomical structures. Remaining incongruities can be recognized and corrected intraoperatively. The achieved reduction can be fixed by the advantages of an internal fixator (locked-screw plate interface). In the period of October 2002 until April 2007 we operated 136 patients with intraarticular fractures of the calcaneus by means of anatomical reduction, and internal plate fixator under intraoperative control of 3D-fluoroscopy. All patients were supplied with an orthesis after the operation which allowed weight bearing of 10 kg for 12 weeks for the patients operated between October 2002 and October 2004 (Group A). Transient local osteoporosis was observed in all X-Rays at follow-up after an average of 8,6 months. Therefore we changed our postoperative treatment plan for the patients operated between November 2004 and April 2007 (Group B). Weight bearing started with 20 KG after 6 weeks, was increased to 40 KG after 8 weeks and full weight bearing was allowed after 10 weeks for these patients. In no case a secondary dislocation of the fracture was seen. No bone graft was used. At follow up the average American Foot and Ankle Society Score (AOFAS) were 81 for Group_A, compared to 84 for Group B, treated with earlier weight bearing. Autologous bone graft was not necessary even if weight bearing was started after a period of six weeks postoperatively. The combination of 3D-fluoroscopy with locked internal fixation showed promising results. If the rate of patients developing subtalar arthrosis will decrease by this management will have to be shown in long term follow up.

[Fracture of the distal lower limb: two-stage surgical treatment with external fixator and locked-screw plate]. / Distale Unterschenkelfraktur: Zweizeitiges Vorgehen mit Fixateur externe und winkelstabiler Platte.

From January 1999 until October 2004 we treated 42 patients with closed fractures of the distal calf by a two-stage treatment plan: first the fracture was stabilized with an external fixator bridging the ankle joint. Second, after an average period of 8.3 days, an open reduction and internal fixation with a locked-screw implant followed. As complications we saw a superficial wound necrosis in 3 cases, 2 patients needed an early bone graft after insufficient bone healing and in one case a deep vein thrombosis of the thigh occurred. A deep infection or osteitis were not seen. 17 patients showed no deficit in the range of movement of the ankle joint compared to their opposite side, 21 patients had a deficit of movement of one third compared to the opposite side and 4 patients suffered from a deficit of (2/3). Radiologically we saw in 31 fractures of the pilon-tibiale in 19 cases no or only few arthrosis of the ankle joint, in 9 cases intermediate and in 3 cases advanced arthrosis. With a two-stage surgical treatment with external fixator and locked-screw implant we achieved a good functional result with only few complications.