Christoph Gonser

High Complication Rate After Biplanar Open Wedge High Tibial Osteotomy Stabilized With a New Spacer Plate (Position HTO Plate) Without Bone Substitute

PURPOSE We performed a prospective clinical and radiographic evaluation after open wedge high tibial osteotomy (HTO) using the new Position HTO plate (Aesculap, Tuttlingen, Germany) without bone transplantation. METHODS Thirty-five open wedge HTOs with the Position HTO plate were performed without bone wedges. The mean patient age was 44.6 ± 9.2 years at the time of osteotomy, which was planned with mediCAD II software (Hectec, Niederviehbach, Germany). The Hospital for Special Surgery score, Lysholm-Gillquist score, Tegner activity level, and International Knee Documentation Committee subjective score were used for clinical assessment. We evaluated radiographs obtained preoperatively and at 2, 6, and 12 months postoperatively using full-weight-bearing anteroposterior whole-leg views and anteroposterior and lateral views of the knee. For statistical analyses, JMP 8.0.1 (SAS, Cary, NC) was used. RESULTS We observed an overall complication rate of 34% and a plate-related complication rate of 23%. Plate-related complications included loss of correction, fracture of the tibial plateau, screw failure, malunion, and fracture of the lateral cortical bone. A significant difference in the mechanical tibiofemoral angle of -1.3° ± 1.4° (P < .001) was found between the follow-up at 2 and 6 months. The mean Hospital for Special Surgery score was 74.8 ± 11.7 preoperatively, and it increased to 87.8 ± 11.0 (P < .001). The mean score on the Lysholm-Gillquist knee functional scoring scale was 55.5 ± 21.7 preoperatively, and it improved to 73.0 ± 23.9 (P < .001). The Tegner activity level was 2.6 ± 0.9 preoperatively, and it improved significantly at final follow-up to 3.7 ± 1.8 (P < .02). The International Knee Documentation Committee subjective score was 43.0 ± 14.9 preoperatively, and it increased to 66.1 ± 21 (P < .001). CONCLUSIONS We have shown a high plate-related complication rate and a significant loss of correction between 2 and 6 months of follow-up after open wedge HTO using the new Position HTO plate without bone wedges. The preoperatively planned mechanical tibiofemoral angle was not achieved. Despite these complications, the clinical outcome improved significantly. The Position HTO plate cannot be recommended with the presented technique. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Computer-assisted periacetabular screw placement: Comparison of different fluoroscopy-based navigation procedures with conventional technique

The current gold standard for operatively treated acetabular fractures is open reduction and internal fixation. Fractures with minimal displacement may be stabilised by minimally invasive methods such as percutaneous periacetabular screws. However, their placement is a demanding procedure due to the complex pelvic anatomy. The aim of this study was to evaluate the accuracy of periacetabular screw placement assessing pre-defined placement corridors and comparing different fluoroscopy-based navigation procedures and the conventional technique. For each screw an individual periacetabular placement corridor was preoperatively planned using the planning software iPlan CMF(©) 3.0 (BrainLAB). 210 screws (retrograde anterior column screws, retrograde posterior column screws, supraacetabular ilium screws) were placed in an artificial Synbone pelvis model (30 hemipelves) and in human cadaver specimen (30 hemipelves). 2D- and 3D-fluoroscopy-based navigation procedures were compared to the conventional technique. Insertion time and radiation exposure to specimen were also recorded. The achieved screw position was postoperatively assessed by an Iso-C(3D) scan. Perforations of bony cortices or articular surfaces were analysed and the screw deviation severity (difference of the operatively achieved screw position and the preoperatively planned screw position in reference to the pre-defined corridors) was determined using image fusion. Using 3D-fluoroscopy-based navigation, the screw perforation rate (7%) was significantly lower compared to 2D-fluoroscopy-based navigation (20%). For all screws, the deviation severity was significantly lower using a 3D- compared to a 2D-fluoroscopy-based navigation and the conventional technique. Analysing the posterior column screws, the screw deviation severity was significantly lower using 3D- compared to 2D-fluoroscopy-based navigation. However, for the anterior column screw, the screw deviation severity was similar regardless of the imaging method. Despite the advantages of the 3D-fluoroscopy-based navigation, this method led to significantly longer total procedure and fluoroscopic times, and the applied radiation dose was significantly higher. Percutaneous periacetabular screw placement is demanding. Especially for posterior column screws, due to a lower perforation rate and a higher accuracy in periacetabular screw placement, 3D-fluoroscopy-based navigation procedure appears to be the method of choice for image guidance in acetabular surgery.

Retrograde lag screw placement in anterior acetabular column with regard to the anterior pelvic plane and midsagittal plane -- virtual mapping of 260 three-dimensional hemipelvises for quantitative anatomic analysis.

Percutaneous screw placement can be used for minimally invasive treatment of none or minimally displaced fractures of the anterior column. The complex pelvic geometry can pose a major challenge even for experienced surgeons. The present study examined the preformed bone stock of the anterior column in 260 hemipelvises (130 male and 130 female). Screws were virtually implanted using iPlan(®) CMF (BrainLAB AG, Feldkirchen, Germany); the maximal implant length and the maximal implant diameter were assessed. The study showed, that 6.5mm can generally be used in men; in women however individual planning is essential in regard to the maximal implant diameter since we found that in 15.4% of women, screws with a diameter less than 6.5mm were necessary. The virtual analysis of the preformed bone stock corridor of the anterior column showed two constrictions of crucial clinical importance. These can be found after 18% and 55% (men) respectively 16% and 55% (women) measured from the entry point along the axis of the implant. The entry point of the retrograde anterior column screw in our collective was located lateral of tuberculum pubicum at the level of the superior-medial margin of foramen obturatum. In female patients, the entry point was located significantly more lateral of symphysis and closer to the cranial margin of ramus superior ossis pubis. The mean angle between the screw trajectory and the anterior pelvic plane in sagittal section was 31.6 ± 5.5°, the mean angle between the screw trajectory and the midsagittal plane in axial section was 55.9 ± 4.6° and the mean angle between the screw trajectory and the midsagittal plane in coronal section was 42.1 ± 3.9° with no significant deviation between both sexes. The individual angles formed by the screw trajectory and the anterior pelvic and midsagittal plane are independent from anthropometric parameters sex, age, body length and weight. Therefore, they can be used for orientation in lag screw placement keeping in mind that the entry point differs in both sexes.

Refrakturen nach Entfernung von Osteosynthesematerialien

ZusammenfassungRefrakturen an den Extremitätenknochen nach Materialentfernung sind eine seltene, aber ernst zu nehmende Komplikation, die in den meisten Fällen einen weiteren Eingriff notwendig machen. In einer retrospektiven Analyse der eigenen Fälle sowie unter Berücksichtigung der vorhandenen Literatur zeigt sich, dass durch eine vollständige präoperative Diagnostik, durch Einhalten eines ausreichenden Intervalls von initialer Osteosynthese bis zur Materialentfernung, durch zurückhaltende Belastung des vorgeschädigten Knochens direkt nach der Materialentfernung und unter Berücksichtigung der Art der Frakturheilung die Komplikationsrate vermindert werden kann. Jedoch ist eine vollständige Vermeidung kaum möglich, da oft der ausdrückliche Wunsch des Patienten zur Materialentfernung vorhanden ist und biomechanisch eine Minderbelastbarkeit durch die residuellen Schraubenlöcher und die Demineralisationszonen im Bereich der ehemaligen Frakturzonen zumindest für einige Wochen postoperativ besteht. Entsprechend sollte in einigen Fällen die Empfehlung zum Verbleib des Osteosynthesematerials ausgesprochen werden.AbstractRefractures of long bones after implant removal are a rare but serious complication, which in most cases make a reoperation necessary. We analysed our own cases and reviewed the scarce literature on this subject. As a result we found that it is possible to reduce this complication by performing thorough preoperative preparation, observing an adequate interim time between initial osteosynthesis and hardware removal, cautiously exposing the weakened bone to force for a certain time period after implant removal and taking the character of the fracture healing into consideration. It is not possible to entirely eradicate this complication because a lot of patients demand the implant removal even though it is known that demineralisation and residual screw holes both induce a reduction of energy-absorbing capacity and therefore predispose the patient to refracture. In some cases the surgeon should recommend that the implants remain in situ.Refractures of long bones after implant removal are a rare but serious complication, which in most cases make a reoperation necessary. We analysed our own cases and reviewed the scarce literature on this subject. As a result we found that it is possible to reduce this complication by performing thorough preoperative preparation, observing an adequate interim time between initial osteosynthesis and hardware removal, cautiously exposing the weakened bone to force for a certain time period after implant removal and taking the character of the fracture healing into consideration. It is not possible to entirely eradicate this complication because a lot of patients demand the implant removal even though it is known that demineralisation and residual screw holes both induce a reduction of energy-absorbing capacity and therefore predispose the patient to refracture. In some cases the surgeon should recommend that the implants remain in situ.

Refracture of long bones after implant removal. An avoidable complication

ZusammenfassungRefrakturen an den Extremitätenknochen nach Materialentfernung sind eine seltene, aber ernst zu nehmende Komplikation, die in den meisten Fällen einen weiteren Eingriff notwendig machen. In einer retrospektiven Analyse der eigenen Fälle sowie unter Berücksichtigung der vorhandenen Literatur zeigt sich, dass durch eine vollständige präoperative Diagnostik, durch Einhalten eines ausreichenden Intervalls von initialer Osteosynthese bis zur Materialentfernung, durch zurückhaltende Belastung des vorgeschädigten Knochens direkt nach der Materialentfernung und unter Berücksichtigung der Art der Frakturheilung die Komplikationsrate vermindert werden kann. Jedoch ist eine vollständige Vermeidung kaum möglich, da oft der ausdrückliche Wunsch des Patienten zur Materialentfernung vorhanden ist und biomechanisch eine Minderbelastbarkeit durch die residuellen Schraubenlöcher und die Demineralisationszonen im Bereich der ehemaligen Frakturzonen zumindest für einige Wochen postoperativ besteht. Entsprechend sollte in einigen Fällen die Empfehlung zum Verbleib des Osteosynthesematerials ausgesprochen werden.AbstractRefractures of long bones after implant removal are a rare but serious complication, which in most cases make a reoperation necessary. We analysed our own cases and reviewed the scarce literature on this subject. As a result we found that it is possible to reduce this complication by performing thorough preoperative preparation, observing an adequate interim time between initial osteosynthesis and hardware removal, cautiously exposing the weakened bone to force for a certain time period after implant removal and taking the character of the fracture healing into consideration. It is not possible to entirely eradicate this complication because a lot of patients demand the implant removal even though it is known that demineralisation and residual screw holes both induce a reduction of energy-absorbing capacity and therefore predispose the patient to refracture. In some cases the surgeon should recommend that the implants remain in situ.Refractures of long bones after implant removal are a rare but serious complication, which in most cases make a reoperation necessary. We analysed our own cases and reviewed the scarce literature on this subject. As a result we found that it is possible to reduce this complication by performing thorough preoperative preparation, observing an adequate interim time between initial osteosynthesis and hardware removal, cautiously exposing the weakened bone to force for a certain time period after implant removal and taking the character of the fracture healing into consideration. It is not possible to entirely eradicate this complication because a lot of patients demand the implant removal even though it is known that demineralisation and residual screw holes both induce a reduction of energy-absorbing capacity and therefore predispose the patient to refracture. In some cases the surgeon should recommend that the implants remain in situ.

Hardware removal after pelvic ring injury

BACKGROUND Pelvic ring fractures are considered as rare injuries. Minimally invasive sacroiliac screw fixation has been used increasingly in recent years as an operative strategy for the treatment of these injuries, if the dorsal pelvic ring needed to be addressed. Treatment options for the anterior pelvic ring comprise plates, screws or external fixation. METHOD Based on the limited number of publications on this subject and our own experience with 80 patients who suffered pelvic ring B- or C-type injuries during a period of 8 years we are able to show that the indication for hardware removal in the pelvic ring should be strictly defined. RESULTS In some cases like external fixation, implant-associated infection, malpositioning, allergic implant reaction, critical soft tissue covering, palpable hardware and consolidated juvenile fractures implant removal is certainly indicated. In patients without symptoms and in patients with trauma-associated symptoms which are not definitely associated with the hardware, the removal should be only indicated after thorough consideration of the risks versus the benefits and additionally by taking the initial injury pattern into account. If despite all these objections the hardware removal has been indicated it should always be considered that hardware removal may be challenging with several possible severe complications.

EASY (endoscopic approach to the symphysis): a new minimally invasive approach for the plate osteosynthesis of the symphysis and the anterior pelvic ring—a cadaver study and first clinical results

BackgroundMinimally invasive surgical approaches to reduce approach-associated morbidity are an interdisciplinary goal in surgery. In principle, the endoscopic approach for the extraperitoneal repair of groin hernias is the minimally invasive variant of the modified Stoppa-approach, which is used for the treatment of pelvic ring injuries in traumatology.MethodAnatomical feasibility study regarding the plate osteosynthesis of the anterior pelvic ring via a minimally invasive variant of the modified Stoppa-approach.ResultsWe present the minimally invasive variant of the modified Stoppa-approach in a human cadaver step by step, both photographically and radiologically. Feasibility of the plate osteosynthesis of the symphysis is presented in a patient with open book injury via the minimally invasive approach using standard laparoscopic instruments.ConclusionThe plate osteosynthesis of the anterior pelvic ring via the minimally invasive variant of the modified Stoppa-approach is feasible with existing standard laparoscopic instruments.

Komplikationen in der Behandlung periprothetischer Frakturen bei einliegender Knietotalendoprothese – eine klinisch-radiologische Outcome-Analyse

Background The incidence of periprosthetic fractures associated with total knee arthroplasty (PpFxK) has been reported to be 0.3 – 5.5%. 40% of all cases are related to revision TKA. The most common localisation is the distal femur. Classification is performed according to Rorabeck (RB). RB I – II fractures are usually treated with locked plating and retrograde intramedullary nailing, whereas RB III fractures are an indication for revision arthroplasty using a hinged endoprosthesis. PpFxK of the patella can be classified according to Goldberg and PpFxK of the proximal tibia can be grouped as in Felix. Interprosthetic fractures can be regarded as a special type of PpFx. Due to the increasing numbers of TKA being performed, increasing numbers of adverse events in arthroplasty can be expected. Adverse events in the treatment of PpFxK occur in up to 41% of patients according to the literature and revision is needed in approximately 29% of all cases. Risk factors are age, osteoporosis, infection, malalignment, osteolysis/loosening of the implant and status post revision. Patients A clinical and radiographic follow-up was performed with 50 patients (14 men, 36 women) treated for PpFxK of the femur, tibia and patella between 2011 and 2015 at the department of arthroplasty at a level 1 trauma center in Europe. Results The follow-up of all patients was 68%, with an average of 19.1 ± 14.6 (1 – 49) months between PpFxK and clinical follow-up. 16% of the patients were allocated for further treatment or revision surgery from other hospitals. The patientsʼ median age was 78.0 ± 8.8 (55 – 94) years. Most patients were affected by several orthopaedic and internal medical comorbidities. PpFxK classified as RB II were the most common fractures (60%, n = 30). PpFxK usually occurred 5.0 ± 4.8 (0 – 20) years after index TKA (primary or revision TKA), mostly in patients with CR-retaining endoprosthesis, whereas PpFxK according to Felix occurred significantly earlier and mostly in hinged TKAs. Patients achieved on average a mean Oxford Knee Score of 31.1 ± 9.9 (14 – 46) points. The functional Knee Society Score (KSS) was 52.6 ± 24.4 (20 – 100) and the mean KSS was 58.7 ± 26.8 (0 – 99) points (n = 25). Radiographic evaluation of the RB I – II patients showed frontal and sagittal malalignment in 20.6% of all cases after reduction and plate fixation. The overall rate of surgical adverse events was 50%; 44% of all RB patients needed revision surgery. Adverse events comprised non-union, failure of osteosynthesis, infection, wound healing disorders and re-fractures in the RB II and the Felix subgroup. Conclusion PpFxK are severe injuries and are associated with a high rate of adverse events related to treatment. Patients often have a complex background and a history of revision surgery or periprosthetic joint infection. The treatment of PpFxK should therefore take place at a centre with expertise in traumatology as well as in revision arthroplasty. Preoperative infection diagnostic testing as well as adequate imaging (X-rays and CT) are essential. We furthermore advise early evaluation of revision arthroplasty, especially in elderly patients suffering from PpFxK with insufficient bone quality around the TKA and closeness between fracture and TKA. In the case of plate fixation, it is important to give attention to correct reduction – to prevent non-union, loosening of the implant and failure of the osteosynthesis – as well as to consider double plating.

Periprosthetic tibial fractures in total knee arthroplasty – an outcome analysis of a challenging and underreported surgical issue

BackgroundPeriprosthetic fractures after total knee arthroplasty (TKA) are an increasing problem and challenging to treat. The tibial side is commonly less affected than the femoral side wherefore few studies and case reports are available. The aim of this study was to analyze the outcome of periprosthetic tibial fractures and compare our data with current literature.MethodsAll periprosthetic tibial TKA fractures that were treated at our Level 1 Trauma Center between 2011 and 2015 were included and analyzed consecutively. The Felix classification was used to assess the fracture type and evaluation included the radiological and clinical outcome (Knee Society Score/KSS, Oxford Knee Score/OKS).ResultsFrom a total of 50 periprosthetic TKA fractures, 9 cases (7 female, 2 male; 2 cruciate retaining, 7 constrained TKAs) involving the tibial side were identified. The mean age in this group was 77 (65–85) years with a follow-up rate of 67% after a mean of 22 (0–36) months. The Felix classification showed type IB (n = 1), type IIB (n = 2), type IIIA (n = 4) and type IIIB (n = 2) and surgical intervention included ORIF (n = 6), revision arthroplasty (n = 1), arthrodesis (n = 1) and amputation (n = 1). The rate of adverse events and revision was 55.6% including impaired wound healing, infection and re-fracture respectively peri-implant fracture. Main revision surgery included soft tissue surgery, arthrodesis, amputation and re-osteosynthesis. The clinical outcome showed a mean OKS of 29 (19–39) points and a functional/knee KSS of 53 (40–70)/41 (17–72) points. Radiological analyses showed 4 cases of malalignment after reduction and plate fixation.ConclusionsPeriprosthetic tibial fractures predominantly affect elderly patients with a reduced bone quality and reveal a high complication rate. Careful operative planning with individual solutions respecting the individual patient condition is crucial. If ORIF with a plate is considered, restoration of the correct alignment and careful soft tissue management including minimal invasive procedures seem important factors for the postoperative outcome.

Refrakturen nach Entfernung von Osteosynthesematerialien@@@Refracture of long bones after implant removal: Eine vermeidbare Komplikation?@@@An avoidable complication?

ZusammenfassungRefrakturen an den Extremitätenknochen nach Materialentfernung sind eine seltene, aber ernst zu nehmende Komplikation, die in den meisten Fällen einen weiteren Eingriff notwendig machen. In einer retrospektiven Analyse der eigenen Fälle sowie unter Berücksichtigung der vorhandenen Literatur zeigt sich, dass durch eine vollständige präoperative Diagnostik, durch Einhalten eines ausreichenden Intervalls von initialer Osteosynthese bis zur Materialentfernung, durch zurückhaltende Belastung des vorgeschädigten Knochens direkt nach der Materialentfernung und unter Berücksichtigung der Art der Frakturheilung die Komplikationsrate vermindert werden kann. Jedoch ist eine vollständige Vermeidung kaum möglich, da oft der ausdrückliche Wunsch des Patienten zur Materialentfernung vorhanden ist und biomechanisch eine Minderbelastbarkeit durch die residuellen Schraubenlöcher und die Demineralisationszonen im Bereich der ehemaligen Frakturzonen zumindest für einige Wochen postoperativ besteht. Entsprechend sollte in einigen Fällen die Empfehlung zum Verbleib des Osteosynthesematerials ausgesprochen werden.AbstractRefractures of long bones after implant removal are a rare but serious complication, which in most cases make a reoperation necessary. We analysed our own cases and reviewed the scarce literature on this subject. As a result we found that it is possible to reduce this complication by performing thorough preoperative preparation, observing an adequate interim time between initial osteosynthesis and hardware removal, cautiously exposing the weakened bone to force for a certain time period after implant removal and taking the character of the fracture healing into consideration. It is not possible to entirely eradicate this complication because a lot of patients demand the implant removal even though it is known that demineralisation and residual screw holes both induce a reduction of energy-absorbing capacity and therefore predispose the patient to refracture. In some cases the surgeon should recommend that the implants remain in situ.Refractures of long bones after implant removal are a rare but serious complication, which in most cases make a reoperation necessary. We analysed our own cases and reviewed the scarce literature on this subject. As a result we found that it is possible to reduce this complication by performing thorough preoperative preparation, observing an adequate interim time between initial osteosynthesis and hardware removal, cautiously exposing the weakened bone to force for a certain time period after implant removal and taking the character of the fracture healing into consideration. It is not possible to entirely eradicate this complication because a lot of patients demand the implant removal even though it is known that demineralisation and residual screw holes both induce a reduction of energy-absorbing capacity and therefore predispose the patient to refracture. In some cases the surgeon should recommend that the implants remain in situ.