Loosening of total knee arthroplasty - always aseptic?

PURPOSE: When revision surgery is needed in total knee arthroplasty (TKA) the most frequent reasons are aseptic loosening (AL) and periprosthetic joint infection (PJI). However preoperative distinction between AL and PJI remains challenging. Aim of this study is to determine the incidence of PJI in patients with suspected AL after TKA and to evaluate a diagnostic algorithm for reliable differential diagnosis. METHODS: In this study a total of 149 symptomatic patients with radiographic signs of prosthetic loosening and suspected AL were included. Preoperatively all patients underwent a standardized diagnostic algorithm. For each patient demographics, as well as the results of laboratory and microbiological testing were collected from the medical records. RESULTS: Of the included patients 117 (78.5%) were diagnosed with AL and 32 (21.5%) with PJI. The latency period from primary arthroplasty to the presentation with symptomatic implant loosening was significantly shorter for PJI compared to AL (p < 0.05). The initial CRP values were significantly higher in patients with PJI compared to patients with AL (p < 0.05). Elevated count of white blood cells or percentage of neutrophils within the synovial fluid support the diagnosis of PJI. The sensitivity of synovial cell count (CC) count for PJI in patients with radiographic signs of loosening was 0.84 (CI 0.81-0.87) with a specificity of 0.96 (CI 0.92-0.98). The single best measure for the diagnosis of PJI was synovial fluid cultures with a specificity of 1, however this measure provides poor sensitivity. CONCLUSION: Patients with radiographic signs of loosening in TKA need thorough diagnostics. Information about primary TKA, serological testing, and results of joint aspiration can rule out a PJI in most cases.

Possible risk factors for acute and chronic deep periprosthetic joint infections in primary total knee arthroplasty. Do BMI, smoking, urinary tract infections, gender, and ASA classification have an impact?

PURPOSE: Aim of this retrospective study was to evaluate the impact of the patient related factors body mass index (BMI), urinary tract infection, current smoking, gender, and American Society of Anesthesiologists (ASA) classification on the incidence of acute and chronic deep periprosthetic joint infections (PJI) in total knee arthroplasty (TKA). METHODS: All patients undergoing revision surgery for a deep PJI of primary TKA between July 2012 and December 2016 were included in this study. All relevant data was collected from the medical records. Acute deep PJI was defined when PJI was diagnosed within the first 6 weeks after primary TKA, chronic PJI was defined when patients demonstrated PJI later than 6 weeks after primary TKA. RESULTS: A total of 57 patients was included in this study with 13 cases of acute PJI and 44 of chronic PJI. Overweight patients (BMI > 25 kg/m2) represent a significantly larger proportion in both PJI groups (p < 0.05). Current smokers had an significantly increased risk for acute and chronic PJI (p < 0.05). In the acute PJI group 46.2% patients had an postoperative urinary tract infection. CONCLUSION: An elevated BMI (>25 kg/m2), current smoking and urinary tract infection are possible risk factors for acute and chronic deep PJI. After primary TKA screening for urinary tract infection is recommendable to prevent predominantly acute deep PJI.

[Evaluation of driving fitness in patients with musculoskeletal disorders : A systematic review]. / Empfehlungen zur Fahrtauglichkeit bei Erkrankungen des Bewegungs- und Stützapparates : Ein systematisches Review.

OBJECTIVE: Driving a motor vehicle is one of the most important aspects of personal mobility in our society. However, there is a lack of evidence regarding driving fitness after orthopedic or trauma surgery-related diseases. Aim of this systematic review was to support the treating physician to determine the individual driving fitness in patients with musculosceletal disorders. MATERIAL AND METHODS: A systematic analysis was performed using the PubMed database. Following a predefined algorithm, all relevant articles published from 2013 to 2018 were included. RESULTS: The results were categorized according to the affected part of the body into I. lower extremity and II. upper extremity. Also, results were subcategorized into movement restrictions caused by external joint-braces, musculoskeletal diseases, and postoperative conditions. CONCLUSION: This article supports the treating physician to individually determine the driving fitness in patients with musculoskeletal disorders. However, only a few standardized tests exist to individually determine the driving fitness in patients with musculoskeletal disorders. A particular shortcoming was observed for impairments of the upper extremity.

Primary cemented bipolar radial head prostheses for acute elbow injuries with comminuted radial head fractures: mid-term results of 37 patients.

BACKGROUND: Radial head arthroplasty represents a widely accepted treatment for elbow injuries with non-reconstructible radial head fractures. The aim of this retrospective multicenter study was to assess mid-term results of patients with clearly defined elbow injuries including type III fractures of the radial head according to Mason's classification type III after primary arthroplasty using a cemented bipolar design. MATERIALS AND METHODS: In 45 cases a primary cemented bipolar arthroplasty of the radial head was implanted for elbow injuries combined with an acute Mason type III radial head fracture. In all patients associated fractures were detected with preoperative CT scans and ligamentous injuries were evaluated and both were addressed intraoperatively based on a standardized algorithm. Patients with associated injuries other than coronoid fractures and collateral ligament tears were excluded from this study to obtain a more homogenous sample. Clinical and radiological assessment was performed on thirty-seven patients at an average of 5.6 years postoperatively. RESULTS: DASH Score, functional rating index of Broberg and Morrey, Mayo Elbow Performance Score, and Mayo Modified Wrist Score confirmed good-to-excellent results in most of the patients. Compared to the unaffected arm range of motion and grip strength were slightly reduced. No elbow instability or loosening of the prosthesis, and minor degenerative changes were detected in a few cases. CONCLUSION: Primary cemented bipolar arthroplasty for type III fractures according to Mason's classification in an elbow injury pattern only including associated coronoid fractures and/or ligamentous tears resulted in good-to-excellent mid-term results. These results suggest that primary bipolar radial head arthroplasty combined with distinct treatment of all associated injuries provides good functional outcomes concerning range of motion, elbow stability, and strength in this cohort. However, the associated injuries may influence clinical and radiological outcome and need to be detected, classified, and treated carefully.

The challenge of Monteggia-like lesions of the elbow: mid-term results of 46 cases.

AIMS: The aim of this retrospective multicentre study was to evaluate mid-term results of the operative treatment of Monteggia-like lesions and to determine the prognostic factors that influence the clinical and radiological outcome. PATIENTS AND METHODS: A total of 46 patients (27 women and 19 men), with a mean age of 57.7 years (18 to 84) who had sustained a Monteggia-like lesion were followed up clinically and radiologically after surgical treatment. The Mayo Modified Wrist Score (MMWS), Mayo Elbow Performance Score (MEPS), Broberg and Morrey Score, and Disabilities of the Arm, Shoulder and Hand (DASH) score were used for evaluation at a mean of 65 months (27 to 111) postoperatively. All ulnar fractures were stabilized using a proximally contoured or precontoured locking compression plate. Mason type I fractures of the radial head were treated conservatively, type II fractures were treated with reconstruction, and type III fractures with arthroplasty. All Morrey type II and III fractures of the coronoid process was stabilized using lag screws. RESULTS: Good results were found for the MMWS, with a mean of 88.4 (40 to 100). There were 29 excellent results (63%), nine good (20%), seven satisfactory (15%), and one poor (2%). Excellent results were obtained for the MEPS, with a mean of 90.7 (70 to 100): 31 excellent results (68%), 13 good (28%), and two fair (4%). Good results were also found for the functional rating index of Broberg and Morrey, with a mean score of 86.6 (57 to 100). There were 16 excellent results (35%), 22 good (48%), six fair (13%), and two poor (4%). The mean DASH score was 15.1 (0 to 55.8). Two patients had delayed wound healing; four patients had nonunion requiring bone grafting. One patient had asymptomatic loosening of the radial head prosthesis. CONCLUSION: Monteggia-like lesions are rare. With correct identification, classification, and understanding using CT scans followed by appropriate surgical treatment that addresses all components of the injury, good to excellent mid-term results can be achieved. Cite this article: Bone Joint J 2018;100-B:212-18.

Treatment of a diaphyseal long-bone defect with autologous bone grafts and platelet-rich plasma in a rabbit model.

INTRODUCTION: Large bone defects are a therapeutic challenge to surgeons and are often associated with a high morbidity. The use of autologous cancellous bone graft represents an essential therapeutic option and is considered the gold standard. However, the use of platelet-rich plasma (PRP) for improving bone defect healing has been discussed controversially. The aim of this study was to evaluate the treatment of a diaphyseal long-bone defect in a rabbit model with a combination of PRP and autologous cancellous bone. MATERIAL AND METHODS: A monocortical long-bone defect in the radial diaphysis of 24 New Zealand white rabbits was filled either with autologous cancellous graft as a control group or with autologous cancellous graft combined with autologous PRP. Histomorphometrical and radiological analysis as well as quantification of platelets and growth factors were performed. The animals were euthanatized after three and six weeks according to the study arms. RESULTS: A significant improvement in bone healing was observed histomorphometrically in the PRP group in the central area of the defect zone (p <0.01) as well as the cortical defect zone (p <0.01). The radiological findings were in accordance with the histomorphometrical results. Comparing native blood and PRP, an enrichment of growth factors and platelets was detectable in the PRP. CONCLUSION: Within this animal study, the combination of PRP and autologous cancellous bone grafts improved bone healing significantly compared to the sole application of autologous bone. Therefore, further efforts should be initiated to establish the composite of PRP and autologous bone for bone healing disorders in clinical use.

Hyperbaric oxygen therapy improves angiogenesis and bone formation in critical sized diaphyseal defects.

Besides the use of autologous bone grafting several osteoconductive and osteoinductive methods have been reported to improve bone healing. However, persistent non-union occurs in a considerable number of cases and compromised angiogenesis is suspected to impede bone regeneration. Hyperbaric oxygen therapy (HBO) improves angiogenesis. This study evaluates the effects of HBO on bone defects treated with autologous bone grafting in a bone defect model in rabbits. Twenty-four New-Zealand White Rabbits were subjected to a unilateral critical sized diaphyseal radius bone defect and treated with autologous cancellous bone transplantation. The study groups were exposed to an additional HBO treatment regimen. Bone regeneration was evaluated radiologically and histologically at 3 and 6 weeks, angiogenesis was assessed by immunohistochemistry at three and six weeks. The additional administration of HBO resulted in a significantly increased new bone formation and angiogenesis compared to the sole treatment with autologous bone grafting. These results were apparent after three and six weeks of treatment. The addition of HBO therapy to autologous bone grafts leads to significantly improved bone regeneration. The increase in angiogenesis observed could play a crucial role for the results observed.

The effect of bone marrow concentrate and hyperbaric oxygen therapy on bone repair.

Neoangiogenesis represents an essential part of bone regeneration. Therefore the improvement of neovascularization is the subject of various research approaches. In addition autologous mesenchymal stem cells concentrate in combination with bone substitute materials have been shown to support bone regeneration. In a rabbit model we examined the proposed synergistic effect of hyperbaric oxygen therapy (HBOT) and bone marrow concentrate (BMC) with porous calcium phosphate granules (CPG) on neoangiogenesis and osseous consolidation of a critical- size defect. The animal groups treated with HBOT showed a significantly higher microvessel density (MVD) by immunhistochemistry. Furthermore HBOT groups presented a significantly larger amount of new bone formation histomorphometrically as well as radiologically. We conclude that the increase in perfusion as a result of increased angiogenesis may play a key role in the effects of HBOT and consequently promotes bone healing.

The early phase influence of bone marrow concentrate on metaphyseal bone healing.

Bone marrow concentrate (BMC) contains high densities of progenitor cells. Therefore, in critical size defects BMC may have the potency to support bone healing. The aim of this study was to investigate the effect of BMC in combination with calcium phosphate granules (CPG) on bone defect healing in a metaphyseal long bone defect in mini-pigs. A metaphyseal critical-size bone defect at the proximal tibia of 24 mini-pigs was filled with CPG combined with BMC, CPG solely (control group) or with an autograft. Radiological and histomorphometrical evaluations after 6 weeks (42 days) showed significantly more bone formation in the BMC group in the central area of the defect zone and the cortical defect zone compared to the CPG group. At the same time the resorption rate of CPG increased significantly in the BMC group. Nevertheless, compared to the BMC group the autograft group showed a significantly higher new bone formation radiologically and histomorphometrically. In BMC the count of mononuclear cells was significantly higher compared to the bone marrow aspirate (3.5-fold). The mesenchymal progenitor cell characteristics of the cells in BMC were confirmed by flow cytometry. Cells from BMC created significantly larger colonies of alkaline phosphatase-positive colony forming units (CFU-ALP) (4.4-fold) compared to cells from bone marrow aspirate. Nevertheless, even in the BMC group complete osseous bridging was only detectable in isolated instances of the bone defects. Within the limitations of this study the BMC+CPG composite promotes bone regeneration in the early phase of bone healing significantly better than the isolated application of CPG. However, the addition of BMC does not lead to a solid fusion of the defect in the early phase of bone healing an still does not represent an equal alternative to autologous bone.

[Interhospital transfer of severely injured patients in Germany. Evaluation of the DGU trauma register]. / Verlegungsrealität schwerverletzter Patienten in Deutschland. Eine Auswertung im TraumaRegister DGU.

BACKGROUND: The TraumaNetzwerk(D) DGU was founded 3 years ago and since then the majority of trauma centers have been registered and organized into regional trauma network services (TNW). Within these networks assessment criteria for transferring patients to higher level hospitals are defined. The purpose of this study was to evaluate the incidence, causes, implications and quality of care for patients with major trauma who were transferred for definitive treatment before implementation of the TraumaNetzwerk(D) DGU in Germany. PATIENT AND METHODS: The data of 19,035 patients listed in the German Trauma Register of the German Society for Trauma Surgery (DGU, 2002-2007) were analyzed. Patients with an injury severity score (ISS) >9 and a blood pressure documented on admission were included into the study. Data were allocated according to patients where therapy was performed completely in the primary hospital of admission (group I; n=16,033; 84.2%) and patients transferred after primary care from one hospital to another centre for definitive care (group II; n=3,002; 15.8%). Comparative parameters were the pattern and severity of injury, physiological state on admission and clinical outcome. RESULTS: Mean ISS and percentage of patients with an ISS ≥25 did not differ significantly between groups. Of the patients who were transferred to a higher level trauma centre (group II) 20.7% needed catecholamines on admission, 10.1% were in shock (blood pressure <90 mmHg) and 2.5% of the patients underwent resuscitation in the emergency department. Patients of group II had a considerably longer hospital stay (31.2±35.5 days) than patients of group I (24.8±27.1 days). Furthermore, treatment costs were significantly higher for group II (I: EUR 23,870; II: EUR 26,054). CONCLUSIONS: A relevant percentage of patients transferred from one hospital to another were hemodynamically and clinically unstable. To what extent the quality of patient transfer and therefore major trauma care is improved by the implementation of regional trauma networks in Germany remains to be seen over the next years.

[Treatment strategy for carpometacarpal fracture dislocation]. / Behandlungsstrategie bei karpometakarpalen Luxationsfrakturen.

Carpometacarpal (CMC) fracture dislocations of the 2nd through 5th ray are rare injuries whose extent is regularly underestimated in the initial radiographic evaluation of the hand. Obtaining a computed tomography scan is imperative due to the radiographic underrepresentation of the full bone and joint injury. Restoration of bone and joint anatomy of the affected region is of paramount import to prevent joint deterioration and loss of hand durability and dexterity. Early surgical intervention can lead to good functional results. Different operative treatment strategies exist with a common approach being Kirschner wire, screw or plate fixation after closed or open fracture reduction and joint relocation.

[The operative treatment of the degenerative rupture of the anterior tibialis tendon]. / Die operative Therapie der degenerativen Tibialis-anterior-Sehnenruptur.

AIM: A degenerative tear of the anterior tibial tendon is a rare event compared to other tendons. The purpose of this study was to evaluate the functional results after surgical refixation. METHOD: In a retrospective study, we report the functional outcome of five consecutive operatively treated patients suffering from a tear close to the insertion site of the anterior tibial tendon. All patients were assessed postoperatively, the AOFAS and Richter scores were obtained and the range of motion in the ankle joint was evaluated. RESULTS: Preoperatively all patients presented with a significant walking impairment due to a reduced active dorsiflexion, so the decision for surgical refixation was made. In all cases an MRI scan was performed preoperatively. Postoperative immobilisation without weight-bearing was done for six weeks. All patients returned to their former activity level, were satisfied with the postoperative result and had a normal gait in the follow-up examination. The range of motion was equal on both sides, the median AOFAS score was 86 and the median Richter score was 90 out of 100. There were no postoperative complications. DISCUSSION: Untreated tears of the anterior tibial tendon lead to significant impairment of the ankle joint and deformities of the foot. There is no consensus about the treatment with recommendations for operative and non-operative treatment. Various surgical procedures have been described. The surgical reconstruction of the tendon leads to a restored function of the ankle joint and allows a normal gait and is therefore desirable. Due to the loss of function and the good results after surgical treatment in our study, the non-operative treatment is not advisable. CONCLUSION: Surgical repair of degenerative tears of the anterior tibial tendon leads to very good functional results and high patient satisfaction.

The progress of early phase bone healing using porous granules produced from calcium phosphate cement.

OBJECTIVE: Bone grafting is a vital component in many surgical procedures to facilitate the repair of bone defects or fusions. Autologous bone has been the gold standard to date in spite of associated donor-site morbidity and the limited amount of available donor bone. The aim of this study was to investigate the progress of bone regeneration and material degradation of calcium phosphate granules (CPG) produced from a calcium phosphate self-setting cement powder compared to the use of autologous bone grafting in the treatment of "critical size defects" on load-bearing long bones of minipigs. METHODS: A critical size defect in the tibial metaphysis of 16 mini-pigs was filled either with autologous cancellous graft or with micro- and macroporous carbonated, apatic calcium phosphate granules (CPG) produced from a calcium phosphate self-setting cement powder. After 6 weeks, the specimens were assessed by X-ray and histological evaluation. The amount of new bone formation was analysed histomorphometrically. RESULTS: The semi-quantitative analysis of the radiological results showed a complete osseous bridging of the defect in three cases for the autograft group. In the same group five animals showed a beginning, but still incomplete bridging of the defect, whereas in the CPG group just two animals developed this. All other animals of the CPG group showed only a still discontinuous new bone formation. Altogether, radiologically a better osseous bridging was observed in the autograft group compared to the CPG group. Histomorphometrical analysis after six weeks of healing revealed that the area of new bone was significantly greater in the autograft group concerning the central area of the defect zone (p<0.001) as well as the cortical defect zone (p<0.002). All defects showed new bone formation, but only in the autograft group defects regenerated entirely. CONCLUSIONS: Within the limits of the present study it could be demonstrated that autologous cancellous grafts lead to a significantly better bone regeneration compared to the application of calcium phosphate granules (CPG) produced from a calcium phosphate self-setting cement powder after 6 weeks. In the early phase of bone-healing, the sole application of CPG appears to be inferior to the autologous cancellous grafts in an in vivo critical size defect on load-bearing long bones of mini-pigs.

[Interruption of the diagnostic algorithm and immediate surgical intervention after major trauma--incidence and clinical relevance. Analysis of the Trauma Register of the German Society for Trauma Surgery]. / Abbruch der Schockraumdiagnostik und Notfalloperation beim Polytrauma--Inzidenz und klinische Relevanz. Eine Auswertung des TraumaRegisters der DGU.

BACKGROUND: Life-threatening situations after multiple trauma which require interruption of the diagnostic algorithm and immediate surgical treatment after admission are a challenge for the multidisciplinary trauma team. The purpose of this study was to evaluate the incidence, causes, implications and relevance of life-threatening situations for major trauma patients after admission to trauma centers. PATIENT AND METHODS: Data of 12,971 patients listed in the German Trauma Register of the German Society for Trauma Surgery (DGU, 2002-2007) were analyzed. Patients with an injury severity score (ISS) > 16, no isolated head injury and primary admission to a trauma center were included. Data were allocated according to patients where the diagnostic algorithm in the resuscitation room was interrupted to perform emergency surgery (group Notop, n = 713, 5.5%) and patients who received early surgical care after completed diagnostics (group Frühop, n = 5,515, 42.5%). Comparative parameters were the pattern and severity of injury, physiological state and clinical outcome. RESULTS: Patients receiving emergency surgery showed an average ISS score of 39 ± 15 points, whereas patients receiving early surgery showed an average ISS of 31 ± 12 points. On admission patients in the emergency surgery group (44%) suffered from hemodynamic shock considerably more often than patients in the early surgery care group (15%, p < 0.001). This was indicated by the significant differences in systolic blood pressure on admission, amount of preclinical substituted volume, base excess on admission and substituted erythrocyte concentrates in early clinical course. Mortality was 46% in the emergency surgery group and 13% in the early surgical care group (p < 0.001). Severe injuries (AIS ≥ 4) of the thorax, abdomen and extremities (including the pelvis) were encountered considerably more often in the emergency surgery group. There was no statistical difference in occurrence of severe head injuries between the groups. Emergency surgery consisted of 50.5% laparatomy, 19.8% craniotomy, 10.0% thoracotomy and 9.3% pelvic surgery. CONCLUSION: Life-threatening situations after major trauma which require immediate surgical intervention in the resuscitation room rarely occur in Germany. Nevertheless, they are associated with a high mortality and prolonged and complex clinical course if primarily survived. Indications and decision-making processes of these challenging situations have to be practiced with standardized algorithms and should be considered for the future education of orthopedic surgeons in Germany.