Pharmacological elevation of sphingosine-1-phosphate by S1P lyase inhibition accelerates bone regeneration after post-traumatic osteomyelitis.

Posttraumatic osteomyelitis and the ensuing bone defects are a debilitating complication after open fractures with little therapeutic options. We have recently identified potent osteoanabolic effects of sphingosine-1-phosphate (S1P) signalling and have now tested whether it may beneficially affect bone regeneration after infection. We employed pharmacological S1P lyase inhibition by 4-deoxypyrodoxin (DOP) to raise S1P levels in vivo in an unicortical long bone defect model of posttraumatic osteomyelitis in mice. In a translational approach, human bone specimens of clinical osteomyelitis patients were treated in organ culture in vitro with DOP. Bone regeneration was assessed by µCT, histomorphometry, immunohistology and gene expression analysis. The role of S1P receptors was addressed using S1PR3 deficient mice. Here, we present data that DOP treatment markedly enhanced osteogenesis in posttraumatic osteomyelitis. This was accompanied by greatly improved osteoblastogenesis and enhanced angiogenesis in the callus accompanied by osteoclast-mediated bone remodelling. We also identified the target of increased S1P to be the S1PR3 as S1PR3-/- mice showed no improvement of bone regeneration by DOP. In the human bone explants, bone mass significantly increased along with enhanced osteoblastogenesis and angiogenesis. Our data suggest that enhancement of S1P/S1PR3 signalling may be a promising therapeutic target for bone regeneration in posttraumatic osteomyelitis.

Medial augmentation plating of aseptic distal femoral nonunions.

BACKGROUND: Distal femur nonunions are well-recognized contributors to persistent functional disability, with limited data regarding their treatment options. In the current study, we asked whether additional medial augmentation plating is a feasible treatment option for patients with aseptic distal femoral nonunion and intact lateral implants. METHODS: We conducted a single-center, retrospective study including 20 patients treated for aseptic distal femoral nonunion between 2002 and 2017. The treatment procedure included a medial approach to the distal femur, debridement of the nonunion site, bone grafting and medial augmentation plating utilizing a large-fragment titanium plate. Outcome measures were bone-related and functional results, measured by the Hospital for Special Surgery Knee Rating Scale (HSS) and the German Short Musculoskeletal Function Assessment questionnaire (SMFA-D). RESULTS: Eighteen of 20 nonunions showed osseous healing at 8.16 ± 5.23 (range: 3-21) months after augmentation plating. Regarding functional results, the mean HSS score was 74.17 ± 11.12 (range: 57-87). The mean SMFA-D functional index was 47.38 ± 16.78 (range 25.74-71.32) at the last follow-up. Index procedure-associated complications included two cases of persistent nonunion and one case of infection. CONCLUSIONS: According to the assessed outcome measures, augmentation plating is a feasible treatment option, with a high proportion of patients achieving bony union and good functional outcomes and a few patients experiencing complications.

Rate of progressive healing with a carbon-fiber orthosis in cases of partial union and nonunion after ankle arthrodesis using the Ilizarov external fixator.

BACKGROUND: The Ilizarov fixator is a popular device for treating arthrodesis of the ankle joint in complex situations. However, the therapy can fail, with nonunion or partial union that might not be load stable. There is the possibility of follow-up surgery or extended wearing of the fixator. Full weight bearing with a carbon orthosis remains another treatment option, which has not yet been investigated.The aim of the study was to determine the rate of progress that can be obtained with a carbon orthosis in cases of partial union or nonunion after fixator removal. METHODS: In this retrospective observational study thirty-three patients received a carbon orthosis after fixator removal due to nonunion or partial union. All patients were allowed to walk with the orthosis under full load. The consolidation rate was determined radiologically and compared with the imaging data obtained during the last follow-up. In addition to demographic data, the Foot and Ankle Ability Measure and pain using a numeric rating scale were determined. Nine patients had to be excluded due to insufficient follow-up, and finally n = 24 patients were included in the study. RESULTS: The average duration of fixator use was 21 weeks (range 15-40 weeks), and the total average follow-up after removal of the fixator was 16 months (range 4- 56). For 14 (58.33%) patients, there was a further increase in consolidation with the orthosis after the fixator was removed. CONCLUSION: The results show that if there is only partial union or nonunion, further consolidations can be achieved after the application of a carbon orthosis. In a difficult patient population, using an orthosis should therefore be attempted to avoid unnecessary revision operations.

Influence of articular step-off on contact mechanics in fractures of the posterolateral-central tibial plateau - a biomechanical study.

BACKGROUND: The posterior quadrants of the tibial plateau are frequently involved in OTA type C tibial plateau fractures. The biomechanical influence of a residual articular step-off of the posterolateral-central (PLC) segment, which is difficult to visualize intraoperatively, remains unclear. Therefore, aim of this study was to investigate the contact area and stress of the tibial plateau in cases of different articular step-offs of the PLC segment. METHODS: Seven human cadaveric knees were used to simulate articular impressions of the PLC segment with step-offs of 1 mm, 3 mm, and 5 mm. The knees were axially loaded up to 150 N during a total of 25 dynamic cycles of knee flexion up to 90°. Pressure mapping sensors were inserted into the medial and lateral joint compartments beneath the menisci to measure articular contact area and stress. RESULTS: Between 60° and 90° of knee flexion, increasing PLC segment impressions of the tibial plateau led to increasing contact stress and a significantly reduced contact area. The largest decrease in the contact area was 30 %, with an articular step-off of 5 mm (0.003). An increase in contact stress, especially from a 3-mm step-off, was measured, with a doubling of the mean contact stress at 3-mm and 5-mm step-offs and 90° knee flexion (p = 0.06/0.05). CONCLUSION: From a biomechanical point of view, posterior impressions of the PLC segment greater than a 1-mm step-off should be addressed as anatomically as possible, especially in active patients with the need for higher knee flexion angles.

Factors influencing the outcome after surgical reconstruction of OTA type B and C tibial plateau fractures: how crucial is the restoration of articular congruity?

INTRODUCTION: Only few and inconsistent data about the impact of articular congruity and tolerable residual intraarticular steps and gaps of the joint surface after tibial plateau fractures exist. Therefore, aim of this study was to investigate the correlation between OTA type B and C tibial plateau fracture outcomes and postoperative articular congruity using computed tomography (CT) data. MATERIALS AND METHODS: Fifty-five patients with a mean age of 45.5 ± 12.5 years and treated for 27 type B and 28 C tibial plateau fractures with pre- and postsurgical CT data were included. Primary outcome measure was the correlation of postoperative intraarticular step and gap sizes, articular comminution area, the postoperative medial proximal tibial angle (MPTA), and the Lysholm and IKDC score. Receiver-operating characteristic (ROC) curves were used to determine threshold values for step and gap heights according to the following outcome scores: IKDC > 70; Lysholm > 80. Secondary outcome measures were the correlation of fracture severity, the number of complications and surgical revisions and the outcome scores, as well as the Tegner activity score before injury and at final follow-up. RESULTS: After a mean follow-up of 42.4 ± 18.9 months, the mean Lysholm score was 80.7 ± 13.3, and the mean IKDC score was 62.7 ± 17.6. The median Tegner activity score was 5 before the injury and 4 at final follow-up (p < 0.05). The intraarticular step height, gap size, comminution area and MPTA deviation were significantly negatively correlated with the IKDC and Lysholm scores. The cutoff values for step height were 2.6 and 2.9 mm. The gap size threshold was 6.6 mm. In total, an average of 0.5 ± 0.8 (range 0-3) complications occurred, and on average, 0.5 ± 1.1 (range 0-7) surgical revisions had to be performed. The number of complications and surgical revisions also had negative impacts on the outcome. Neither fracture severity nor BMI or patient's age was significantly correlated with the IKDC or Lysholm score. CONCLUSIONS: Tibial plateau fractures are severe injuries, which lead to a subsequent reduced level of patient activity. Precise reconstruction of the articular surface with regard to intraarticular step and gap size, residual comminution area and joint angle is decisive for the final outcome. Complications and surgical revisions also worsen it. LEVEL OF EVIDENCE: III.

Locking the Taylor Spatial Frame - The effect of three additional longitudinal rods on osteotomy site movements.

BACKGROUND: In clinical practice, even when the fixator is locked, a noticeable laxity of the construct can be observed. This study was designed to measure the stiffness of the fixator and to analyze the movements of the osteotomy site. Furthermore, the effect of three additional longitudinal rods on the locking of the construct was analyzed. METHODS: Five synthetic tibia/fixator models (Model A) were tested under rotational torque (40 Nm) and axial compression (700 N). Three additional rigid rods were subsequently mounted, and the tests were repeated (Model B). The movements of the fixator as well as the osteotomy site were registered by a digital optical measurement system. Load- deformation curves, and so stiffness of the models, were calculated and compared. FINDINGS: Under rotational and axial loadings, Model A was found to be less rigid than Model B (p = 0.034; p = 0.194). Notably, Model A showed a region of laxity around neutral rotational (ΔF = 5 Nm) and axial (ΔF = 16.64 N) loading before a linear deformation trend was measured. Concomitantly, greater osteotomy site movement was measured for Model A than for Model B under full loading (p = 0.05) and within the region of increased laxity (p = 0.042). INTERPRETATION: The fixator showed an element of laxity around neutral axial and rotational loading, which transferred to the bone and led to a notable amount of osteotomy gap movement. Mounting three additional rods increased the stiffness of the construct and therefore reduced the movement of the osteotomy site.

The Use of the Ilizarov Fixator for the Treatment of Open and Closed Tibial Shaft and Distal Tibial Fractures in Patients with Complex Cases.

INTRODUCTION: Open and closed fractures of the tibial shaft or distal tibia can be challenging for surgeons to treat if the fractures are accompanied by aggravating conditions, such as various accompanying diseases, pronounced soft tissue injuries, osteomyelitis, and/or noncompliance. The aim of this retrospective study was to present our approach and results with the Ilizarov fixator as a treatment option for such individually complex cases. MATERIALS AND METHODS: Between 2005 and 2018, 20 patients were treated with the Ilizarov fixator for fractures of the tibial shaft/distal tibia. The indication for this was a 2nd- to 3rd-degree open fracture in 10 patients, a 1st-degree open fracture in one patient, and closed fractures in 9 patients. Aggravating conditions included soft tissue injuries, osteomyelitis, leg deformities, multiple traumas, smoking, alcohol/drug abuse, and obesity (BMI > 60). In addition to demographic data, the time of fixator treatment, complications, and the endpoint of consolidation were evaluated retrospectively. RESULTS: The mean time of fixator treatment was 29 (range 15-65) weeks. Complete fracture consolidation was achieved in 13 patients (65%) with the Ilizarov fixator. The mean follow-up period after fixator removal was 36 (range 2-186) months in 14 patients. Five patients with complete consolidation were lost to further follow-up. One patient was amputated. In six patients without union, internal osteosynthesis was carried out. CONCLUSION: The use of the Ilizarov fixator is a treatment option for individual high-risk patients with complicating courses but should be seen as a salvage procedure due to the high complication rate and long treatment process.

Injuries after Forklift Trucks Accidents - Injury Patterns, Therapy and Outcome in the Context of the Statutory Accident Insurance. / Gabelstaplerunfälle ­ Verletzungsmuster, Therapie und Outcome im berufsgenossenschaftlichen Kontext.

INTRODUCTION: The use of forklift trucks during work has a high accident potential. The aim of this study is to describe injury patterns, treatment and outcome after forklift truck accidents in the context of the employers' liability insurance association. METHODS: Retrospective data collection of all cases between 2004 and 2019. Excluded were patients < 18 years, without follow-up or with definitive external treatment. Trauma mechanism, injury patterns and distribution, treatment, complications, time of incapacity for work, return to work and impairment of earning capacity were recorded. RESULTS: Of 109 patients with 110 injuries, 52.7% showed isolated injuries and 47.3% combined injuries, which affected the lower extremity in 95 cases. There were fractures in 85.5%, including 32.7% in open form. The mean length of stay was 29.1 days (range 1 - 129); an indication for surgery was seen in 80.9%. Surgical treatment required an average of 3 interventions, with significantly more operations for soft tissue closure than for the fractures (p ≤ 0.023). Amputations were necessary in 8 cases; complications occurred in 29.1%. Return to work was possible in 90%, after a mean period of incapacity for work of 33.6 weeks. A total of 40% showed a pensionable impairment of earning capacity. CONCLUSION: Accidents with forklift trucks result in complex lower extremities injuries with the need of multi-stage treatment and show relatively high complication rates. A return to work is often possible after a long period of convalescence, and a pensionable impairment of earning capacity often persists.

Wnt3a and ASCs are capable of restoring mineralization in staph aureus-infected primary murine osteoblasts.

INTRODUCTION: Bone infections are one of the main reasons for impaired bone regeneration and non-union formation. In previous experimental animal studies we could already demonstrate that bone defects due to prior infections showed a markedly reduced healing capacity, which could effectively be enhanced via application of Wnt3a and Adipose-derived stromal cells (ASCs). For a more in-depth analysis, we investigated proliferation and mineralization of cultured osteoblasts infected with staph aureus and sought to investigate effects of Wnt3a and ASCs on infected osteoblasts. MATERIALS AND METHODS: Primary murine osteoblasts were isolated from calvariae and infected with staph aureus. Infected osteoblasts received treatment via application of recombinant Wnt3a, ASC conditioned medium and were furthermore cocultured with ASCs. Osteoblasts were evaluated by Alamar blue assay for metabolic activity, TUNEL-assay for apoptosis, ALP and Alizarin Red staining for mineralization. In addition, immunoflourescent staining (IF) and qRT-PCR analyses were performed. RESULTS: Infected osteoblasts showed a markedly reduced ability for mineralization and increased apoptosis, which could be restored to physiological levels by Wnt3a and ASC treatment. Interestingly, metabolic activity of osteoblasts seemed to be unaffected by staph aureus infection. Additional analyses of Wnt-pathway activity revealed effective enhancement of canonical Wnt-pathway activity in Wnt3a-treated osteoblasts. CONCLUSIONS: In summary, we gained further osteoblast-related insights into pathomechanisms of reduced bone healing capacity upon infections.

Comparative analysis of clinical outcome and quality of life between amputations and combined bone and flap reconstructions at the lower leg.

PURPOSE: At the lower leg, soft tissue defects with exposed bones, tendons, or hardware require flap coverage. In this retrospective study, we analyzed combined bone and soft tissue reconstructions compared to amputations of the lower leg in a civilian setting. MATERIALS AND METHODS: Patients who underwent combined bone and flap reconstruction (LR) or amputation (LA) of the lower leg were eligible for the study. Bone conditions included fractures and bony defects due to posttraumatic osteomyelitis and non-union. Besides the analysis of the medical history, the study included clinical examination including extremity functional scale (LEFS) and SF-36-questionnaire. RESULTS: LEFS score was significantly higher in the LR group compared to the LA group. Importantly, 42% in the LR group as opposed to 80% in the LA group could not return to their occupation. Mean hospitalization was 119 in the LR and 49 days in the LA group. SF-36 body item scores were significantly higher in the LR group as compared to LA. CONCLUSIONS: Patients undergoing complex extremity reconstructions, including flap transfer to the lower leg have better functionality and higher quality of life than amputated patients. These data emphasize the advantages of these procedures and justify reconstructive efforts for limb salvage. Level of Evidence III.Implications for RehabilitationAmputation and combined bone and flap reconstruction in severe injuries of the lower leg can imply functional disabilities even after successful treatment.Albeit longer hospitalizations, patients with complex reconstructions showed better functional outcomes and had a higher quality of life.Limb salvage showed better functional outcomes and a higher rate in reintegration to work as compared to limb amputation.These data emphasize the importance of complex bone and soft tissue reconstruction in this patient cohort.

Simultaneous septic arthrodesis of the tibiotalar and subtalar joints with the Ilizarov external fixator-an analysis of 13 patients.

PURPOSE: Treatment of joint destruction of the tibiotalar and subtalar joints caused by acute or chronic infections in compromised hosts is a challenging problem. In these cases, simultaneous septic arthrodesis with the use of the Ilizarov external fixator represents a possible alternative to amputation. This case series presents the results and complications of patients with acute or chronic infection of the tibiotalar and subtalar joints. METHODS: Between 2005 and 2015, 13 patients with acute or chronic infections were treated by simultaneous single-stage debridement/arthrodesis of the tibiotalar and subtalar joints. In seven patients, there was a florid infection with fistula formation and soft tissue defects, and in six patients, there was chronic osteomyelitis with closed soft tissue. In addition to the demographic data, the time spent in the fixator, the major and minor complications and the endpoint of consolidation were reviewed. RESULTS: The mean time spent in the fixator was 18 (min 15, max 26) weeks. The mean follow-up time for nine patients was 100 (min 3, max 341) weeks. Complete osseous consolidation of both the tibiotalar and subtalar joints was achieved in 10 patients (77%). In three (23%) patients, there was complete consolidation of one of the joints and partial consolidation of the other joint. CONCLUSION: The Ilizarov external fixator allows for simultaneous arthrodesis of the tibiotalar and subtalar joints in septic joint destruction. However, the healing rates are below the rates reported in the literature for isolated tibiotalar or tibiocalcaneal arthrodesis in comparable clinical situations.

Tibiocalcaneal arthrodesis using the Ilizarov fixator in compromised hosts: an analysis of 19 patients.

INTRODUCTION: Salvage of joint destruction of the tibiotalar and subtalar joint with necrosis or infection of the talus in compromised hosts is a challenging problem. In these cases, tibiocalcaneal arthrodesis using the Ilizarov external fixator represents a possible alternative to amputation. This retrospective study presents the results and complications of this salvage procedure. MATERIALS AND METHODS: Between 2005 and 2015, 19 patients were treated with tibiocalcaneal arthrodesis using the Ilizarov external fixator. Ten patients received tibiocalcaneal arthrodesis due to an acute or chronic infection with joint destruction. The other nine patients presented posttraumatic necrosis of the talus or Charcot arthropathy. In addition to demographic data, the time spent in the fixator, the major and minor complications and the endpoint of the consolidation were evaluated retrospectively. Furthermore, clinical outcomes were measured using the modified American Orthopedic Foot and Ankle Society (AOFAS) score. RESULTS: The average time spent in the fixator was 22 (range 14-34) weeks. The average follow-up in 17 patients was 116 (range 4-542) weeks. Two patients were lost to follow-up. Complete osseous consolidation was achieved in 14 out of 19 patients. One patient presented partial consolidation, and in four patients, pseudarthrosis could be detected. The mean modified AOFAS score at the final follow-up was 53 out of 86 possible points. CONCLUSION: Tibiocalcaneal arthrodesis using the Ilizarov fixator is a possible salvage procedure even in compromised hosts. However, the healing rates are below the rates reported in the literature for tibiotalar arthrodesis in comparable clinical situations.

Analysis of bone transport for ankle arthrodesis as a limb salvage procedure for the treatment of septic pilon fracture nonunion.

Septic nonunion of the pilon region with ankle joint infection is challenging for orthopedic surgeons to treat and is associated with a high risk of limb loss. Therefore, the aim of this study was to evaluate the effectiveness of bone transport for ankle arthrodesis in salvaging the limp after septic ankle destruction of the pilon region. We conducted a single-center, retrospective study including 21 patients treated for septic pilon nonunion with accompanying septic ankle destruction via Ilizarov bone transport between 2004 and 2018. In all cases, the complete excision of the nonunion and the resection of the ankle joint were carried out, followed by treating the bone and joint defect with a bone transport into the ankle arthrodesis. In 12/21 patients an additional flap transfer was required due to an accompanying soft tissue lesion. The overall healing and failure rate, final alignment and complications were recorded by the patients' medical files. The bone-related and functional results were evaluated according to the Association for the Study and Application of Methods of Ilizarov (ASAMI) scoring system and a modified American Orthopedic Foot and Ankle Society (AOFAS) scale. After a mean follow-up of 30.9 ± 15.7 months (range 12-63 months), complete bone and soft tissue healing occurred in 18/21 patients (85.7%). The patients had excellent (5), good (7), fair (4), and poor (3) results based on the ASAMI functional score. Regarding bone stock, 6 patients had excellent, 7 good, and 6 fair results. The modified AOFAS score reached 60.6 ± 18 points (range, 29-86). In total, 33 minor complications and 28 major complications occurred during the study period. In 2 cases, a proximal lower leg amputation was performed due to a persistent infection and free flap necrosis with a large soft tissue defect, whereas in one case, persistent nonunion on the docking side was treated with a carbon orthosis because the patient refused to undergo an additional surgery. Bone transport for ankle arthrodesis offers the possibility of limb salvage after septic ankle destruction of the pilon region, with acceptable bony and functional results. However, a high number of complications and surgical revisions are associated with the treatment of this severe complication after pilon fracture.

Reconstruction of Septic Tibial Bone Defects With the Masquelet Technique and External Ring Fixation-A Low Healing Rate and High Complication and Revision Rates.

OBJECTIVES: To evaluate the results of a series of septic tibial bone defects treated with the Masquelet technique and external ring fixation as a standardized treatment procedure. DESIGN: Retrospective study. SETTING: Level one trauma center. PATIENTS/PARTICIPANTS: All patients 18 years of age or older with septic diaphyseal bone defects of the tibia who underwent induced membrane treatment with ring fixation at our institution between June 1, 2012, and November 31, 2017. INTERVENTION: Staged management as described by Masquelet using an external ring fixator for definitive fixation. MAIN OUTCOME MEASUREMENTS: Bony healing at the last follow-up and the time to healing in months. Functional results were assessed according to the scoring system of the Association for the Study and Application of Methods of Ilizarov. The secondary outcome measures were treatment failure and complications. RESULTS: Thirty-one patients were treated, with a mean follow-up period of 33 months (range, 13-69 months). Overall, among 14 patients assessed as having achieved bone healing, an average of 3.7 surgical revisions were required. The mean healing time was 15.5 months (range, 6-49 months). According to the Association for the Study and Application of Methods of Ilizarov criteria, 7 patients were rated as "excellent" and 6 patients were rated as "good"; one patient showed "poor" functional results. A total of 17 cases of treatment failure and 36 complications were detected. CONCLUSIONS: The combination of the Masquelet technique and external fixation yielded a low healing rate and was associated with a significant number of cases of treatment failure. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Long-term follow up of extensor tendon ruptures of the knee using electromyography and three-dimensional gait analysis.

BACKGROUND: The aim of this study was to analyze the long-term outcomes of extensor tendon ruptures of the knee using exact measuring tools. METHODS: The results of patients treated for extensor tendon rupture with a minimum follow up of 10 years were reviewed. Electromyography (EMG) and three-dimensional (3D) gait analyses were performed and compared with the healthy side of each patient and with the gait patterns of 20 healthy controls. Functional outcome scores were assessed using the Lysholm score and Knee Injury and Osteoarthritis Outcome Score (KOOS). RESULTS: After a mean of 13.4 ± 3 years, 23 patients were available for follow up. The mean Lysholm score was 86.6, and the KOOS averaged 78.1. Gait analysis showed no major kinematic differences between these patients compared with healthy controls. In the squat test, the mean peak amplitude of the rectus femoris muscle was significantly smaller on the injured side than on the healthy side (140.21 ± 66.13 µV vs. 168.25 ± 91.77 µV; P = 0.01). The mean peaks of the vastus lateralis and medialis EMG signals were also lower on the injured side (P = 0.63; P = 0.08). Correspondingly, the thigh girth at 20 cm and 10 cm above the knee was significantly lower on the injured side. One patient had re-rupture after patella tendon repair. CONCLUSION: At long-term follow up the patients reached good clinical outcomes and exhibited mainly physiological gait patterns after rupture of knee extensor tendons. However, the thigh muscles showed hypotrophy and a significantly smaller EMG signal amplitude during a high-intensity task on the formerly injured side.

Anatomical repair and ligament bracing of Schenck III and IV knee joint dislocations leads to acceptable subjective and kinematic outcomes.

PURPOSE: The aim of this study was to analyze the outcomes of anatomical repair and ligament bracing for Schenck III and IV knee dislocation (KD). METHODS: The results of 27 patients (15 and 12 cases of Schenck III and IV KD, respectively) after a mean follow-up of 18.1 ± 12.1 months (range 6-45 months) were retrospectively reviewed. Twenty-two patients suffered high-kinetic-energy accidents, whereas five patients suffered ultralow-velocity (ULV) trauma due to obesity. The outcome measures were the Lysholm score, Hospital for Special Surgery (HSS) knee score, Knee Society Score (KSS), Knee Injury and Osteoarthritis Outcome Score (KOOS) and Short Form 36 (SF-36) score. A kinematic 3D gait analysis with five walking trials was performed to compare the patients and healthy controls. RESULTS: The mean KSS, HSS score, Lysholm score, and KOOS were 77.4 ± 14.4, 84.6 ± 11.2, 81.5 ± 10.4, and 67.3 ± 16.8, respectively. No intra- or postoperative complications occurred. The mean range of motion deficiency compared to the healthy side was 24.4 ± 18.5°. Ten patients had first-degree residual laxity of the anterior cruciate ligament; 12 and 2 patients had first- and second-degree residual laxity of the collateral ligament, respectively. Five patients underwent additional arthroscopic arthrolysis due to arthrofibrosis at an average of 6.2 ± 1.9 months (range 4-9 months) after the initial surgery. The 3D gait analysis showed no major differences in joint stability or movement between the patients and healthy controls. Only the ULV trauma patients had significantly lower outcome scores and showed larger kinematic deviations in joint movement during the gait analysis. CONCLUSION: Anatomical repair with ligament bracing is a suitable surgical procedure in the treatment of KD and provides evidence in clinical practice with the benefit of early, definitive repair and preservation of the native ligaments. Patients reach acceptable subjective and objective functional outcomes, including mainly normalized gait patterns during short-term follow-up, with only minor changes in kinematics and spatial-temporal characteristics. Obese patients who suffered ULV trauma showed significantly inferior outcomes with larger deviations in joint kinematics. LEVEL OF EVIDENCE: Level III.

Ilizarov bone transport using an intramedullary cable transportation system in the treatment of tibial bone defects.

INTRODUCTION: Segmental tibia defects remain challenging for orthopedic surgeons to treat. The aim of this study was to demonstrate bone-related and functional outcomes after treatment of complex tibial bone defects using Ilizarov bone transport with a modified intramedullary cable transportation system (CTS). PATIENTS AND METHODS: We conducted a single-center, retrospective study including all 42 patients treated for tibial bone loss via Ilizarov bone transport with CTS between 2005 and 2018. Bone-related and functional results were evaluated according to the Association for the Study and Application of Methods of Ilizarov (ASAMI) scoring system. Complication and failure rates were determined by the patients' medical files. RESULTS: Patients had a mean age of 45.5 ± 15.1 years. The mean bone defect size was 7.7 ± 3.4 cm, the average nonunion scoring system (NUSS) score was 59 ± 9.5 points, and the mean follow-up was 40.8 ± 24.4 months (range, 13-139 months). Complete bone and soft tissue healing occurred in 32/42 patients (76.2%). These patients had excellent (10), good (17), fair (2), and poor (3) results based on the ASAMI functional score. Regarding bone stock, 19 patients had excellent, 10 good, and 3 fair results. In total, 37 minor complications and 62 major complications occurred during the study. In 7 patients, bone and soft tissue healing occurred after CTS failure with either an induced membrane technique or classic bone transport; 3 patients underwent lower leg amputation. Patients with treatment failure were significantly older (57.6 vs. 41.8 years; p = 0.003). Charlson score and treatment failure had a positive correlation (Spearman's rho 0.43; p = 0.004). CONCLUSION: Bone transport using both intramedullary CTS and Ilizarov ring fixation is viable for treating patients with bone loss of the tibia and complex infection or soft tissue conditions. However, a high number of complications and surgical revisions are associated with the treatment of this severe clinical entity and should be taken into account.

Biomechanical comparison of screw osteosyntheses and anatomical plating for coronoid shear fractures of the ulna.

INTRODUCTION: Among the few techniques described for the treatment of coronoid fractures, osteosynthesis techniques include screw osteosynthesis from anterior to posterior (AP) or from posterior to anterior (PA) and plate osteosynthesis. The aim of this study was to test the biomechanical stability of screw osteosynthesis and plate osteosynthesis using anatomical plates in coronoid process fractures. MATERIALS AND METHODS: On a total of 25 biomechanical synthetical ulnae, a coronoid shear fracture including 70% of the coronoid height was simulated. Osteosynthesis was then performed using two 2.7 mm screws from anterior, posterior and with use of three different anatomical plates of the coronoid process. For the biomechanical testing, axial load was applied to the fragment with 1000 cycles from 5 to 250 N, load to failure and load at 100 µm displacement. Displacements were measured using a point-based three-dimensional motion analysis system. RESULTS: Osteosynthesis using the PA-screw showed significant more displacement during cyclic loading compared with all other osteosyntheses (0.99 mm), whereas AP-screw showed the smallest displacement (0.10 mm) during cyclic loading. The PA-screw technique showed a significant lower load to failure compared to all other osteosynthesis with the highest load in AP-screw osteosynthesis. The load for 100 µm displacement was the smallest in PA-screw with a significant difference to the AP-screw and one plate osteosynthesis. CONCLUSION: Osteosynthesis of large coronoid shear fractures with two small-fragment screws from anterior allows stable fixation that is not inferior to anterior plate osteosynthesis and might be an alternative in specific fracture types. Posterior screw fixation was found as the weakest fixation method. LEVEL OF EVIDENCE: Basic science study.

Treatment of aseptic nonunion after medial opening-wedge high tibial osteotomy.

BACKGROUND: Nonunion after medial opening-wedge high tibial osteotomy (OWHTO) is a rare but serious complication with very limited data regarding its treatment. The aim of this study was to analyze the healing rate after operative treatment of nonunion after OWHTO. METHODS: We performed a single-center, retrospective study that included 14 patients with nonunion after OWHTO between 2010 and 2018. The treatment for all patients consisted of local debridement and cancellous bone grafting at the osteotomy gap. Revision osteosynthesis due to a loss of correction/loosening of the locking screws or plates was performed in 5 patients. In 7 patients, lateral hinge fractures were treated with additional lateral plating. Union was confirmed using the modified "Radiographic Union Score for Tibial fractures". Outcome measure was the Lysholm Knee Score at final follow-up. RESULTS: The mean age of the patients included in our study was 48.4 ± 6.7 years. Three patients were female (21.4%). The mean follow-up period was 20.8 ± 12.8 months. Union was achieved in 12/14 patients (85.7%) after a mean of 6 months (range, 3-13). The mean Lysholm Knee Score at the final follow-up was 83.2 ± 11.6. Two patients did not reach definitive union during the follow-up. In one patient, an infection of the nonunion following bone grafting was successfully treated with a two-stage procedure. Two patients needed additional cancellous bone grafting 6 and 8 months after the first revision surgery. All patients showed pain-free full weight bearing after union was achieved. CONCLUSIONS: Nonunions after OWHTO can generally be treated successfully with cancellous bone grafting. For patients who have loss of correction, loosening of the osteosynthetic material or fracture of the lateral hinge, an additional revision or additive osteosynthesis may be required. LEVEL OF EVIDENCE: Grade III.

Spinal Cord Injury With Tetraplegia in Young Persons After Diving Into Shallow Water: What Has Changed in the Past 10 to 15 Years?

STUDY DESIGN: Retrospective, monocentric, observational study in a tertiary health care center. OBJECTIVES: To analyze prehospital and clinical findings, complications, neurological improvement and follow-up in a young person cohort with spinal cord injury (SCI) and tetraplegia according to the American Spinal Injury Association (ASIA) Impairment Scale (AIS) A to D after diving into shallow water. METHODS: Included were all persons younger than 50 years with SCI after head-first diving into shallow water between June 2001 and June 2019. All persons with SCI were divided into complete tetraplegia (AIS A) and incomplete tetraplegia (AIS B, C, and D) to test differences. RESULTS: A total of 59 males (98.7%) and 1 female with a mean age of 27.7 years suffered an SCI. Alcohol use was documented in 25 cases (41.7%). At the time of admission, 33 people (55%) showed a complete tetraplegia (AIS A) and 27 showed an incomplete tetraplegia with 8 AIS B (13.3%), 15 AIS C (25%), and 4 AIS D (6.7%). At the time of discharge, people with initially complete tetraplegia showed a significant improvement from admission to discharge (P ≤ .004). Persons with incomplete tetraplegia were more likely to improve their neurological status compared with complete tetraplegia patients (P ≤ .001). Especially persons with complete tetraplegia suffered from typical SCI-related problems and complications. CONCLUSIONS: People with SCI and tetraplegia at the time admission show neurological improvement in 50% of the cases with an overall better outcome in persons with incomplete tetraplegia. The surgical treatment of SCI within 24 hours seems to be associated with a better neurological outcome and a lower level of tetraplegia. The incidence of SCI caused by diving into shallow water remains stable without a significant change, especially in high-risk groups. More education and prevention programs are necessary to avoid these injuries.