Standardized artificially created stable pertrochanteric femur fractures present more homogenous results compared to osteotomies for orthopaedic implant testing.

BACKGROUND: With regard to biomechanical testing of orthopaedic implants, there is no consensus on whether artificial creation of standardized bone fractures or their simulation by means of osteotomies result in more realistic outcomes. Therefore, the aim of this study was to artificially create and analyze in an appropriate setting the biomechanical behavior of standardized stable pertrochanteric fractures versus their simulation via osteotomizing. METHODS: Eight pairs of fresh-frozen human cadaveric femora aged 72.7 ± 14.9 years (range 48-89 years) were assigned in paired fashion to two study groups. In Group 1, stable pertrochanteric fractures AO/OTA 31-A1 were artificially created via constant force application on the anterior cortex of the femur through a blunt guillotine blade. The same fracture type was simulated in Group 2 by means of osteotomies. All femora were implanted with a dynamic hip screw and biomechanically tested in 20° adduction under progressively increasing physiologic cyclic axial loading at 2 Hz, starting at 500 N and increasing at a rate of 0.1 N/cycle. Femoral head fragment movements with respect to the shaft were monitored by means of optical motion tracking. RESULTS: Cycles/failure load at 15° varus deformation, 10 mm leg shortening and 15° femoral head rotation around neck axis were 11324 ± 848/1632.4 ± 584.8 N, 11052 ± 1573/1605.2 ± 657.3 N and 11849 ± 1120/1684.9 ± 612.0 N in Group 1, and 10971 ± 2019/1597.1 ± 701.9 N, 10681 ± 1868/1568.1 ± 686.8 N and 10017 ± 4081/1501.7 ± 908.1 N in Group 2, respectively, with no significant differences between the two groups, p ≥ 0.233. CONCLUSION: From a biomechanical perspective, by resulting in more consistent outcomes under dynamic loading, standardized artificial stable pertrochanteric femur fracture creation may be more suitable for orthopaedic implant testing compared to osteotomizing the bone.

Long-term follow-up after MIPO Philos plating for proximal humerus fractures.

INTRODUCTION: Minimally invasive plate osteosynthesis (MIPO) has been described as a suitable technique for the treatment of proximal humerus fractures, but long-term functional results have never been reported. The aim of this study was to describe the long-term functional outcome and implant-related irritation after MIPO for proximal humerus fractures. METHODS: A long-term prospective cohort analysis was performed on all patients treated for a proximal humerus fracture using MIPO with a Philos plate (Synthes, Switzerland) between December 2007 and October 2010. The primary outcome was the QuickDASH score. Secondary outcome measures were the subjective shoulder value (SSV), implant related irritation and implant removal. RESULTS: Seventy-nine out of 97 patients (81%) with a mean age of 59 years were available for follow-up. The mean follow-up was 8.3 years (SD 0.8). The mean QuickDASH score was 5.6 (SD 14). The mean SSV was 92 (SD 11). Forty out of 79 patients (50.6%) had implant removal, and of those, 27/40 (67.5%) were due to implant-related irritation. On average, the implant was removed after 1.2 years (SD 0.5). In bivariate analysis, there was an association between the AO classification and the QuickDASH (p = 0.008). CONCLUSION: Treatment of proximal humerus fractures using MIPO with Philos through a deltoid split approach showed promising results. A good function can be assumed due to the excellent scores of patient oriented questionnaires. However, about one-third of the patients will have a second operation for implant removal due to implant-related irritation.

Biomechanical evaluation of a new gliding screw concept for the fixation of proximal humeral fractures.

AIMS: Plating displaced proximal humeral fractures is associated with a high rate of screw perforation. Dynamization of the proximal screws might prevent these complications. The aim of this study was to develop and evaluate a new gliding screw concept for plating proximal humeral fractures biomechanically. METHODS: Eight pairs of three-part humeral fractures were randomly assigned for pairwise instrumentation using either a prototype gliding plate or a standard PHILOS plate, and four pairs were fixed using the gliding plate with bone cement augmentation of its proximal screws. The specimens were cyclically tested under progressively increasing loading until perforation of a screw. Telescoping of a screw, varus tilting and screw migration were recorded using optical motion tracking. RESULTS: Mean initial stiffness (N/mm) was 581.3 (sd 239.7) for the gliding plate, 631.5 (sd 160.0) for the PHILOS and 440.2 (sd 97.6) for the gliding augmented plate without significant differences between the groups (p = 0.11). Mean varus tilting (°) after 7500 cycles was comparable between the gliding plate (2.6; sd 1.9), PHILOS (1.2; sd 0.6) and gliding augmented plate (1.7; sd 0.9) (p = 0.10). Similarly, mean screw migration(mm) after 7500 cycles was similar between the gliding plate (3.02; sd 2.85), PHILOS (1.30; sd 0.44) and gliding augmented plate (2.83; sd 1.18) (p = 0.13). Mean number of cycles until failure with 5° varus tilting were 12702 (sd 3687) for the gliding plate, 13948 (sd 1295) for PHILOS and 13189 (sd 2647) for the gliding augmented plate without significant differences between the groups (p = 0.66). CONCLUSION: Biomechanically, plate fixation using a new gliding screw technology did not show considerable advantages in comparison with fixation using a standard PHILOS plate. Based on the finding of telescoping of screws, however, it may represent a valid approach for further investigations into how to avoid the cut-out of screws.Cite this article: Y. P. Acklin, I. Zderic, J. A. Inzana, S. Grechenig, R. Schwyn, R. G. Richards, B. Gueorguiev. Biomechanical evaluation of a new gliding screw concept for the fixation of proximal humeral fractures. Bone Joint Res 2018;7:422-429. DOI: 10.1302/2046-3758.76.BJR-2017-0356.R1.

Are two retrograde 3.5 mm screws superior to one 7.3 mm screw for anterior pelvic ring fixation in bones with low bone mineral density?

OBJECTIVES: Osteosynthesis of anterior pubic ramus fractures using one large-diameter screw can be challenging in terms of both surgical procedure and fixation stability. Small-fragment screws have the advantage of following the pelvic cortex and being more flexible.The aim of the present study was to biomechanically compare retrograde intramedullary fixation of the superior pubic ramus using either one large- or two small-diameter screws. MATERIALS AND METHODS: A total of 12 human cadaveric hemipelvises were analysed in a matched pair study design. Bone mineral density of the specimens was 68 mgHA/cm3 (standard deviation (sd) 52). The anterior pelvic ring fracture was fixed with either one 7.3 mm cannulated screw (Group 1) or two 3.5 mm pelvic cortex screws (Group 2). Progressively increasing cyclic axial loading was applied through the acetabulum. Relative movements in terms of interfragmentary displacement and gap angle at the fracture site were evaluated by means of optical movement tracking. The Wilcoxon signed-rank test was applied to identify significant differences between the groups RESULTS: Initial axial construct stiffness was not significantly different between the groups (p = 0.463). Interfragmentary displacement and gap angle at the fracture site were also not statistically significantly different between the groups throughout the evaluated cycles (p ⩾ 0.249). Similarly, cycles to failure were not statistically different between Group 1 (8438, sd 6968) and Group 2 (10 213, sd 10 334), p = 0.379. Failure mode in both groups was characterised by screw cutting through the cancellous bone. CONCLUSION: From a biomechanical point of view, pubic ramus stabilisation with either one large or two small fragment screw osteosynthesis is comparable in osteoporotic bone. However, the two-screw fixation technique is less demanding as the smaller screws deflect at the cortical margins.Cite this article: Y. P. Acklin, I. Zderic, S. Grechenig, R. G. Richards, P. Schmitz, B. Gueorguiev. Are two retrograde 3.5 mm screws superior to one 7.3 mm screw for anterior pelvic ring fixation in bones with low bone mineral density? Bone Joint Res 2017;6:8-13. DOI: 10.1302/2046-3758.61.BJR-2016-0261.

Cost of skeletal complications from bone metastases in six European countries.

Objective Patients with bone metastases or lesions secondary to solid tumors or multiple myeloma often experience bone complications (skeletal-related events [SREs]-radiation to bone, pathologic fracture, surgery to bone, and spinal cord compression); however, recent data that can be used to assess the value of treatments to prevent SREs across European countries are limited. This study aimed to provide estimates of health resource utilization (HRU) and cost associated with all SRE types in Europe. HRU data were reported previously; cost data are reported herein. Methods Eligible patients from 49 centers across Austria (n = 57), the Czech Republic (n = 59), Finland (n = 60), Greece (n = 59), Portugal (n = 59), and Sweden (n = 62) had bone metastases or lesions secondary to breast, lung, or prostate cancer, or multiple myeloma, and ≥1 index SRE (a SRE preceded by a SRE-free period of ≥ 6.5 months). SRE-related costs were estimated from a payer perspective using health resource utilization data from patient charts (before and after the index SRE diagnosis). Country-specific unit costs were from 2010 and local currencies were converted to 2010 euros. Results The mean costs across countries were €7043, €5242, €11,101, and €11,509 per radiation to bone, pathologic fracture, surgery to bone, and spinal cord compression event, respectively. Purchasing power parity (PPP)-adjusted mean cost ratios were similar in most countries, with the exception of radiation to bone. Limitations The overall burden of SREs may have been under-estimated owing to home visits and evaluations outside the hospital setting not being reported here. Conclusions All SREs were associated with substantial costs. Variation in SRE-associated costs between countries was most likely driven by differences in treatment practices and unit costs.

Clinical and radiologic outcomes associated with the use of dynamic locking screws (DLS) in distal tibia fractures.

BACKGROUND: The locked screw plate construct is often cited as being too rigid and prolonging healing in patients with metaphyseal fractures. The newly introduced dynamic locking screws (DLS) allow 0.2 mm of axial motion, which should optimize healing near the near cortex. The purpose of this study was to analyze the clinical results of dynamic locking screws in distal tibia fractures. METHODS: Data were acquired retrospectively. Only distal meta-diaphyseal tibia fractures treated with minimally invasive plate osteosynthesis and DLS were evaluated. Cortical and locking head screws were used for distal plate fixation to minimize soft tissue irritation over the medial malleolus, and DLS were used in the proximal plate fixation. Clinical and radiographic data were evaluated after 6 weeks, 3 months, 6 months and 1 year until fracture union. RESULTS: Twenty-two patients were treated with minimally invasive plate osteosynthesis and DLS. Six patients could not be evaluated because they returned to a foreign residence after the procedure. Fourteen fractures healed after a mean of 3.1 months. Two fractures with insufficient reduction showed delayed union and healed after 9 and 9.5 months, respectively. The callus index peaked at 6 months. CONCLUSIONS: Dynamic fracture fixation might be a promising concept to reduce the frequency of metaphyseal non-unions in distal tibia fractures. But nevertheless, the dynamic construct cannot compensate for insufficient reduction.

Extended medial approach in posteromedial proximal tibia fracture dislocation.

OBJECTIVE: Treatment of posteromedial proximal tibia fracture dislocation (medial Moore type II, Schatzker IV) with a one-incision technique. INDICATIONS: Posteromedial proximal tibia fracture dislocation Moore type II (medial). CONTRAINDICATIONS: All Moore type V fracture patterns requiring a bilateral approach. SURGICAL TECHNIQUE: In supine position, an extended strictly medial incision is performed. It is mandatory to preserve the medial collateral ligament and the pes anserinus. In a first step, the posterolateral impressed zone is reduced directly through the main fracture gap using an image intensifier. The posteromedial main fragment is then reduced and preliminarily fixed with Kirschner wires. A posteromedial buttress plate slid in under the medial ligamentous structures supports this fragment. Anterior subcutaneous dissection revolves the medial boarder of the patellar ligament and a medial arthrotomy is performed. The bony avulsed anterior cruciate ligament (ACL) is reduced and suture fixation follows. POSTOPERATIVE MANAGEMENT: Immediate partial weight bearing is possible. RESULTS: A collective of 26 patients could be evaluated after a median follow-up of 4 years (1-8 years). Median age was 51 years (20-77 years). All fractures healed without secondary displacement or infection. After a median of 4 years, 25 patients showed no to moderate osteoarthritis. One patient showed severe osteoarthritis after 8 years. All patients subjectively judged the clinical result as good to excellent. The average Lysholm score was 95 (75-100) and the average Tegner activity score 5 (3-7).

Double locking plate fixation of sacral fractures in unstable pelvic ring C-type injuries.

OBJECTIVE: Alternative sacrum fixation with double-plate osteosynthesis in vertical unstable pelvic fractures. The surgical technique allows anatomic reduction and osteosynthesis of the sacrum component. INDICATIONS: All vertical unstable pelvic ring fractures 61-C type according to AO/OTA system with associated displaced sacrum fractures CONTRAINDICATIONS: Hemodynamic unstable patients, fractures with major sacroiliac joint involvement, nondisplaced sacrum fractures. SURGICAL TECHNIQUE: In prone position, a midline incision exposing the sacrum fracture is needed. The fracture is distracted and interjacent bone fragments or hematoma can be evacuated. The fracture is anatomically reduced and compressed. Two anatomically bent 3.5-mm locked compression plates (LCP) are placed on the dorsal aspect of the sacrum. In Denis type II and III fractures, the lateral screws can be placed in the lateral aspect of the sacrum. In Denis type I fractures, the lateral screws are placed in the ilium lateral to the sacroiliac joint to improve purchase. Additional short monocortical locking screws in the middle part of the plates increase the vertical stability to the osteosynthesis. Fracture fixation of the anterior ring follows the dorsal procedure. POSTOPERATIVE MANAGEMENT: The patient is mobilized with partial weight bearing. Clinical and radiological follow-up is planned after 6 and 12 weeks. RESULTS: A total of 27 patients with vertical unstable pelvic fractures were identified and treated with open reduction and double-plate osteosynthesis. The Iowa pelvic score was rated excellent in 83 % and good in 17 % of cases. One patient developed a nonunion and had to be revised.

[Chronic ankle joint instability: in unrecognized distal rupture of the syndosmosis and malunion of the distal fibula]. / Chronische obere Sprunggelenkinstabilität : Bei nicht erkannter distaler Syndesmosenruptur und Malunion der Fibulaspitze.

BACKGROUND: It is often difficult in the acute phase to diagnose a lesion of the distal tibiofibular syndesmosis. If this lesion is overlooked, the patient will develop an incongruity of the upper ankle joint with a pathological external rotation of the talus. The risk of a possible premature arthritis is clearly increased. OBJECTIVES: In this case study a distal rupture of the syndesmosis in a young patient was overlooked in the initial diagnostic work-up. METHODS: A search of the relevant literature and a case report. RESULTS: In the case described the shortened fibula and chronic instability of the tibiofibular syndesmosis were repaired with a lengthening and derotational osteotomy and reconstruction using the gracilis muscle tendon. Through this method an exact reconstruction of the normal anatomy could be achieved. CONCLUSION: Posttraumatic misalignment in the ankle joint is associated with a high risk of secondary degenerative lesions. In cases with suspicion of a syndesmosis lesion, confirmation of the diagnosis is imperative so as to perform an anatomic repositioning and reconstruction of stability.

[Multidirectional locking volar plate in distal radius fractures. Secondary loss of reduction--correct implantation is essential]. / Mulitdirektional winkelstabile volare Platte bei distaler Radiusfraktur. Sekundärer Repositionsverlust--Entscheidend ist die richtige Implantation.

In recent years a trend has evolved from unidirectional to multidirectional locking plates. Different technical solutions have been developed and the quality of the angle stability of all methods has been described as sufficient. Published trials describing the necessary shearing forces are rarely published. We report two cases with loss of reduction after the use of a variable angle locking implant used in distal radius fractures.

Plate fixation of proximal humerus fractures using the minimally invasive anterolateral delta split approach.

OBJECTIVE: Minimally invasive plate osteosynthesis of proximal humerus fractures via an anterolateral delta split approach. INDICATIONS: All proximal humerus fractures classified as 11-A1-3, 11-B1-2 (B3), and 11-C1-2 (C3) according to the AO/OTA system. CONTRAINDICATIONS: Head split and closed irreducible dislocation type fractures, fractures with primary neurovascular impairment, and fractures in children with open growth plate. SURGICAL TECHNIQUE: Beach chair position. Anterolateral delta split approach. Maintain rotator cuff insertions with nonabsorbable sutures. Reduction and K-wire retention of the tuberosities to the head fragment. Establish a tunnel along the anterolateral aspect of the proximal humerus with a blunt instrument (e.g., elevatorium). Attachment of the rotator cuff sutures to the corresponding plate holes of a 5-hole PHILOS® plate. Insertion of the plate underneath the deltoid muscle along the prepared tunnel. Preliminary fixation of the plate to the humerus head. Distal alignment of the plate and preliminary fixation. Reduction of the fracture onto the plate with a cortical screw in the shaft segment. Definitive plate fixation in the shaft and head segment. The nonabsorbable sutures are then tightened onto the plate. POSTOPERATIVE MANAGEMENT: Immediate guided active exercise is encouraged. Weight bearing is increased according to radiological signs of consolidation. RESULTS: In a prospective evaluation from 2003-2006, 29 patients (8 male and 21 female) with a mean age of 64 years (16-91 years) were analyzed. The mean follow-up time was 12 months (6-32 months). The operation was accomplished in 75 min (55-155 min) with an image intensifier time of 160 s (48-807 s). All fractures healed in a timely manner. The median Constant score reached 78 points (28-93 points). In one case (3%), clinical evidence of a lesion of the anterior branch of the axillary nerve was found.

[Acute bleeding from the innominate artery after removal of percutaneous tracheotomy]. / Akute Truncus-brachiocephalicus-Blutung nach Entfernung einer perkutanen Dilatationstracheotomie.

Percutaneous tracheotomy is a standard procedure in intensive care units. Even though complications associated with this intervention have been described, acute massive bleeding from the innominate artery is rare and necessitates immediate intervention. We report a case with acute bleeding after removal of a percutaneous tracheotomy cannula.

[Common fractures in a general practice: indication for operations and modern operative technique]. / Die häufigsten Frakturen in der Hausarztpraxis: Operationsindikationen und moderne Operationstechniken.

Distal radius, clavicle, malleolar and proximal humerus fractures belong to the most frequent fracture types in every day practice. The initial diagnose with conservative therapy or the postoperative care is often carried out by the general practitioner. In recent years, therapy modality of these fractures changed. With the development of angular stable implants and minimal invasive operations technique, operative treatment is favoured mainly in osteoporotic bone. The mentioned fractures are highlighted.

Nine-year results of Müller cemented titanium Straight Stems in total hip replacement.

At the Orthopaedic Department of the University of Basel, a total of 540 cemented Müller titanium alloy (Ti6Al7Nb) Straight Stems were inserted between 1989 and 1993. A cohort of 120 consecutive patients (66 women, 54 men) with 126 prostheses operated on between March and December 1989 were followed clinically and radiologically in a prospective manner for a mean observation time of 9.1 years. In all cases, the Müller titanium alloy Straight Stem was combined with the senior author's (E.W.M.) Press-Fit Cup. The mean age of the patients at surgery was 66 (range 43-93) years. Fourty patients (41 hips) died, 9 were interviewed by telephone, none was 'lost to follow-up'. Seventy-one patients with 76 hip replacements were available for the follow-up. Four hips had been revised: two of them due to aseptic loosening of the femoral component, one because of a late infection--all after 9 years--and one owing to a periprosthetic fracture after 6 years. The 9-year overall survivorship is 96.8%, and for aseptic loosening of the stem 98.4%. None of the cups had to be revised for aseptic loosening. The clinical result (according to Merle d'Aubigné) was excellent and good in 88%, moderate in 8%, and poor in 4%. The radiological analysis showed no osteolysis or radiolucent lines in 59 prostheses (78%). Nine stems (12%) showed a radiolucent line. Focal osteolysis was detected in 8 cases (10%) in one or more Gruen zones. The distribution of the osteolyses shows that predominantly zones VII, VI, V, and II are affected in decreasing frequency. No osteolysis was detected on the acetabular side. Our results do not confirm the high rate of osteolysis and revisions with the Müller titanium alloy Straight Stem presented by some other institutions. The verdict on a specific endoprosthetic implant must be made by combined assessment of the design, the implant surface condition, the material, the cement, the cementing procedure and the operative technique. The statement made in earlier publications that cemented titanium alloy should not be used as a femoral stem prosthesis should be reconsidered.