Mid-term clinical and sonographic outcomes of minimally invasive acromioclavicular joint reconstruction: mini-open versus arthroscopically assisted.

INTRODUCTION: The current literature describes various operative stabilization strategies which achieve good clinical outcomes after acute acromioclavicular joint (ACJ) dislocation. The aim of this study was to compare the mid-term clinical and sonographic treatment outcomes after minimally invasive mini-open and arthroscopic reconstruction. MATERIALS AND METHODS: We conducted a retrospective two-center study of patients with acute ACJ dislocation. Surgical treatment was performed using either a mini-open approach (MIOP) or an arthroscopic technique (AR). The primary outcome parameters of this study were the sonographically measured acromioclavicular (ACD) and coracoclavicular distances (CCD). Secondary outcome parameters included the Constant-Murley score (CS), range of motion (ROM), postoperative pain scale (VAS), return to daily routine, return to sports, complications, as well as operative revisions. RESULTS: After a mean follow-up of 29 months, 30 patients were included in this study with an average age of 41.3 ± 14.8 years (MIOP) and 41.2 ± 15.4 years (AR). The sonographic ACD (MIOP 9.11 mm vs. AR 8.93 mm, p = 0.41) and CCD (MIOP 25.08 mm vs. AR 24.36 mm, p = 0.29) distances showed no statistically significant differences. Furthermore, there was no statistically significant difference when compared to the contralateral side (p = 0.42). With both techniques, patients achieved excellent clinical outcome parameters without statistically significant differences in CS (MIOP 95 vs. AR 97, p = 0.11) and VAS (MIOP 1.76 vs. AR 1.14, p = 0.18). The return to daily activity and return to sport rates did not differ. There were neither complications nor revisions in both groups. CONCLUSION: Both minimally invasive techniques for acute ACJ stabilization achieved excellent clinical and sonographic outcomes without one technique being statistically superior to the other.

Acromioclavicular joint suture button repair leads to coracoclavicular tunnel widening.

PURPOSE: Biomechanical evaluation of three different suture button devices used in acromioclavicular joint repair and analysis of their effect on post-testing tunnel widening. METHODS: Eighteen human shoulder girdles were assigned into three groups with a similar mean bone mineral density. Three different single-tunnel acromioclavicular repair devices were tested: (1) AC TightRope® with FiberWire; (2) AC Dog Bone™ Button with FiberTape; (3) Low Profile AC Repair System. Biomechanical testing was performed simulating the complex movement of the distal clavicle as follows. A vertical load of 80 N was applied continuously. The rotation of the clavicle about its long axis was set at 10° anterior and 30° posterior for 2500 cycles at 0.25 Hz. The horizontal translation of the clavicle was set at 6 mm medial and 6 mm lateral for 10,000 cycles at 1 Hz. The coracoclavicular distance was measured before and after testing. After testing, each sample underwent micro-CT analysis. Following 3D reconstruction, the area of the bone tunnels was measured at five defined cross sections. RESULTS: In TightRope® and Dog Bone™ groups, all samples completed testing, whereas in the Low Profile group, three out of six samples showed system failure. The mean absolute difference of coracoclavicular distance after testing was significantly greater in the Low Profile group compared to TightRope® and Dog Bone™ groups (4.3 ± 1.3 mm vs 1.9 ± 0.7 mm vs 1.9 ± 0.8 mm; p = 0.001). Micro-CT analysis of the specimens demonstrated significant tunnel widening in the inferior clavicular and superior coracoid regions in all three groups (p < 0.05). CONCLUSION: Significant tunnel widening can be observed for all devices and is primarily found in the inferior parts of the clavicle and superior parts of the coracoid. The Low Profile AC Repair System showed inferior biomechanical properties compared to the AC TightRope® and AC Dog Bone™ devices. Therefore, clinicians should carefully select the type of acromioclavicular repair device used and need to consider tunnel widening as a complication.

All-suture anchor pullout results in decreased bone damage and depends on cortical thickness.

PURPOSE: To evaluate the influence of cortical and cancellous bone structure on the biomechanical properties of all-suture and conventional anchors and compare the morphological bone damage after their failure. The hypothesis of the study is that all-suture anchor pullout is less invasive and that the pullout force is influenced by the cortical thickness. METHODS: Thirty human humeri were biomechanically tested as follows: starting with a load cycle from 20 to 50 N, a stepwise increase of the upper peak force by 0.05 N for each cycle at a rate of 1 Hz was performed. Analysis included maximum pullout strength for three different anchor implantation angles (45°, 90°, 110°) of the two anchor types. After anchor pullout, every sample underwent micro-CT analysis. Bone mineral density (BMD) and cortical thickness were determined at the anchor implantation site. Furthermore, the diameter of the cortical defect and the volume of the bone cavity were identified. RESULTS: The maximum pullout strength of all-suture anchors demonstrates a strong correlation to the adjacent cortical thickness (r = 0.82, p ≤ 0.05) with at least 0.4 mm needed to withstand 200 N. No correlation could be seen in conventional anchors. Moreover, no correlation could be detected for local BMD in both anchors. All-suture anchors show a significantly narrower cortical defect as well as a smaller bone cavity following pullout (4.3 ± 1.3 mm vs. 5.3 ± 0.9 mm, p = 0.037; 141 mm3 vs. 212 mm3; p = 0.009). The cortical defect is largest if the anchors are placed at a 45° angle. CONCLUSION: In contrast to conventional anchors, the pullout force of all-suture anchors depends on the thickness of the humeral cortex. Furthermore, all-suture anchors show a significantly smaller cortical defect as well as decreased bone damage in the case of pullout. Therefore, the clinical implication of this study is that all-suture anchors are advantageous due to their bone preserving ability. Also, intraoperative decortication should not be performed and cortical thickness should be preoperatively evaluated to decrease the risk of anchor failure.

Implementation of a multidisciplinary infections conference affects the treatment plan in prosthetic joint infections of the hip: a retrospective study.

INTRODUCTION: Establishing a systematic multidisciplinary approach in the treatment of prosthetic joint infections (PJI) of the hip and analyzing its effect on clinical decision-making. PATIENTS AND METHODS: Forty-six patients diagnosed with PJI of the hip were included in the retrospective study. The treatment plan was either established by a single-discipline approach (n = 20) or by a weekly multidisciplinary infections conference (n = 26) consisting of at least an orthopedic surgeon, microbiologist and pathologist. Recorded data included the length of hospital stay, number and type of surgeries, medical complications, recovered organisms as well as the number of applied antibiotics. RESULTS: Patients discussed in the multidisciplinary infections conference showed a significantly shorter in-hospital stay (29 vs 62 days; p < 0.05), a significant reduction in surgeries (1.8 vs 5.1; p < 0.05) and a smaller number of antibiotics required (2.8 vs 4.2; p < 0.05). No significant difference could be found comparing inpatient complications between the two groups. Staphylococcus aureus and coagulase-negative staphylococci were the most frequently recovered organisms in both patient groups. CONCLUSION: This study demonstrates the successful implementation of a weekly infections conference as an instrument to introduce a multidisciplinary approach to PJI of the hip. Implementation of these conferences significantly improves the treatment plan compared to a single-discipline approach, which we therefore highly recommend for other institutions. Multidiscipline may even affect clinical outcome which needs to be further investigated.

Incidence and severity of malreduction of the tibiofibular syndesmosis following surgical treatement of displaced ankle fractures and impact on the function -Clinical study and MRI evaluation.

PURPOSE: To compare tibiofibular reduction quality in different types of operatively treated ankle fractures and the impact on clinical and functional outcome at mid-term follow-up. PATIENTS AND METHODS: One hundred patients with an acute ankle fracture who had undergone open reduction and internal fixation were included. Eighty-eight patients who suffered from ligamentous ankle injury with neither fracture nor syndesmotic lesions served as a control group. Tibiofibular alignment was measured on MR images in all 188 patients. In case of tibiofibular malreduction tibiotalar positioning was determined as well. Clinical and functional outcome was assessed using the AOFAS hindfoot score as well as the SF-36. RESULTS: No tibiofibular malreduction was found in type Weber B fractures, irrespective of syndesmotic instability followed by syndesmotic screw placement, as compared to the control group. A significant tibiofibular malreduction was detected in bimalleolar/trimalleolar/dislocated type Weber B fractures and in isolated type Weber C fractures with syndesmotic screw, in comparison to the control group. Tibiotalar displacement could not be detected. Clinical and functional outcome analysis revealed no significant differences between the treatment groups. CONCLUSION: Three-dimensional imaging may improve tibiofibular malreduction visualization in bimalleolar/trimalleolar/dislocated type Weber B fractures and in isolated type Weber C fractures with syndesmotic transfixation. The clinical impact of improving tibiofibular positioning remains highly questionable since there was no correlation between tibiofibular alignment and the clinical outcome at mid-term follow-up.

[Salmonella osteomyelitis - a rare differential diagnosis of bone tumors]. / Salmonellenosteomyelitis ­ eine seltene Differenzialdiagnose eines Knochentumors.

This case describes a rare salmonella infection suspected to be an osseous lymphoma. A 27-year-old female presented herself with painful swelling of her knee, with prednisolone-treated Crohn's disease as her only pre-existing condition. Salmonella species group C were detected in the osseous material derived from an extraction. The disease was treated with intravenous ceftriaxone, oral cotrimoxazole as well as multiple debridements. The working diagnosis should thus always be questioned and bone pain in patients who are immunosuppressed should be further investigated.

Accuracy of Latarjet graft and screw position after using novel drill guide.

PURPOSE: For the success of Latarjet procedure a correct graft positioning is mandatory. Furthermore, the correct screw placement is important to avoid cartilage damage and soft tissue irritation. Due to a cadaveric experimental study, the accuracy of graft and screw positioning utilizing a novel drill guide for a minimal-invasive Latarjet procedure was analyzed. METHODS: Five human fresh-frozen shoulder specimens have been treated in accordance with the Congruent-Arc Latarjet technique using the glenoid bone loss set (Arthrex, Naples, FL, USA) with 3.75 mm cannulated screws throughout a 5 cm skin incision without detachment of the scapularis tendon. All procedures were performed by one single, experienced shoulder surgeon. The accuracy of graft and screw positioning was assessed due to a CT scan. RESULTS: A noticeable learning curve was noted during the study period as the first surgery took 45 min and the last 33 min. All grafts were correctly positioned with regard to the articular line of the glenoid surface. Impingement with the maximum head circumference was not encountered. The screw positions did not affect the suprascapular nerve. A damage of the graft was not noticed. CONCLUSIONS: The authors can recommend the usage of the new drill guide tested in this study. It seems to be beneficial in the Latarjet procedure and may ease correct graft positioning and prevent screw misplacement. Compared to fully arthroscopically performed Latarjet procedures it provides much steeper learning curve and seems technically easier and quicker to handle.

The Singh Index does not correlate with bone mineral density (BMD) measured with dual energy X-ray absorptiometry (DXA) or peripheral quantitative computed tomography (pQCT).

The Singh Index (SI), a classification system by which the severity of osteoporosis is assessed based on plain radiographs, is a renowned, simple and inexpensive form of evaluating osteoporosis. The aim of this study was to evaluate the correlation between the SI and bone mineral density (BMD) as measured by dual energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT). The SI was evaluated in 128 cadaveric femora (64 patients, mean age 66.7 years, range 24-89 years) by three independent observers, all blinded to plain radiographs. BMD was also analysed by means of DXA and pQCT in the cadaveric femora. The mean interrater correlation was found to be 0.629. The correlation of the mean BMD measured by DXA (DXA-BMD) and SI was found to be poor, with r = 0.49. The corresponding sensitivity of 45.2 % and specificity of 92.3 % were even poor. The BMD measured by pQCT (pQCT-BMD) also revealed a poor correlation with SI, such that r = 0.337 and r = 0.428 for the trochanteric and neck regions, respectively. Due to the poor correlation of the SI with BMD and the poorer interrater correlation, the SI should be rejected as a tool for evaluating osteoporosis. The SI was found to be too imprecise and is therefore unsuitable for diagnosing osteoporosis and osteopenia.

[Primary meningococcal infection of the knee. A rare cause of septic arthritis]. / Primäre Meningokokkeninfektion des Kniegelenks. Eine seltene Ursache einer septischen Arthritis.

This article presents a case of primary septic arthritis of the knee due to serogroup C Neisseria meningitidis. A 19-year-old female presented to the emergency department with a painless but swollen knee joint which had started 2 days previously and fever (38 °C). The patient reported that she suddenly felt unwell 3 days ago and developed a rush at the same time which had almost disappeared when arrived at the emergency department. The patient was admitted to hospital and an antibiotic therapy was started with sulbactam and ampicillin. Initially, incubation of synovial fluid over the next 3 days did not result in detection of any pathogens; therefore, a reactive arthritis was assumed until Neisseria meningitidis was detected in cultures of the synovial fluid. Therapy was then switched to antibiotic therapy with ceftriaxon and arthroscopic irrigation was performed. The patient quickly recovered and was discharged from hospital after 14 days. This case example shows the difficulties of the clinical and microbiological diagnostics of a primary septic meningococcal arthritis; however, the treatment is relatively easy and mostly successful compared to other forms of bacterial joint infection.

Single-stage revision for fungal peri-prosthetic joint infection: a single-centre experience.

Fungal peri-prosthetic infections of the knee and hip are rare but likely to result in devastating complications. In this study we evaluated the results of their management using a single-stage exchange technique. Between 2001 and 2011, 14 patients (ten hips, four knees) were treated for a peri-prosthetic fungal infection. One patient was excluded because revision surgery was not possible owing to a large acetabular defect. One patient developed a further infection two months post-operatively and was excluded from the analysis. Two patients died of unrelated causes. After a mean of seven years (3 to 11) a total of ten patients were available for follow-up. One patient, undergoing revision replacement of the hip, had a post-operative dislocation. Another patient, undergoing revision replacement of the knee, developed a wound infection and required revision 29 months post-operatively following a peri-prosthetic femoral fracture. The mean Harris hip score increased to 74 points (63 to 84; p < 0.02) in those undergoing revision replacement of the hip, and the mean Hospital for Special Surgery knee score increased to 75 points (70 to 80; p < 0.01) in those undergoing revision replacement of the knee. A single-stage revision following fungal peri-prosthetic infection is feasible, with an acceptable rate of a satisfactory outcome.

[Non-traumatic anterior knee dislocation in a patient with osteoarthritis of the knee]. / Atraumatische anteriore Kniegelenksluxation bei Pangonarthrose.

Complete knee dislocation is a rare and severe injury and usually follows high-energy trauma. Non-traumatic knee dislocations are exceedingly rare, while severe overweight appears to be the main cause of the knee dislocation. We here report on a spontaneous knee dislocation in a patient with severe osteoarthritis of the left knee. A 68-year-old woman was admitted to our hospital for an elective total knee replacement. One year prior to admission, a planned joint replacement was not performed due to an existing ulcus cruris. After healing of the ulcus cruris, the patient presented with progressive pain and instability of the left knee without any trauma. The clinical examination showed a multidirectional instability of the left knee with a restricted range of motion (ROM) with 0-0-40 degrees for extension and flexion. The performed radiological examination revealed an anterior knee dislocation of the left knee. Intraoperative findings suggest a non-traumatic aetiology. We suspect that osteoarthritis of the left knee has caused the dislocation. Therefore, we recommend, even in usually "harmless" osteoarthritis, close clinical and radiological follow-up examinations to detect and treat possible complications.

Infection rates in patients undergoing primary knee arthroplasty with pre-existing orthopaedic fixation-devices.

BACKGROUND: Prior knee surgery in the setting of knee arthroplasty (KA) can influence the overall outcome of the procedure and render the operation more technically challenging. The effects of residual fixation devices on subsequent procedures about the knee are ill-defined. Some authors claim an increase in periprosthetic infection in this cohort of patients. The objective of this study was to evaluate the overall incidence of periprosthetic infections in patients undergoing primary KA with pre-existing osteosynthetic hardware in situ. METHODS: The current investigators retrospectively reviewed 124 patients undergoing knee arthroplasty and removal of orthopaedic fixation devices, due to prior high tibial osteotomies, fracture fixation or cruciate ligament reconstruction. The exclusion criterion was a prior history of infection of the fixation device. The mean follow-up time was 5.4 years (range 15 months to 9 years). Nine patients were lost to follow-up. RESULTS: Joint aspiration was performed two weeks prior to surgery in 53 patients (42.4%) and intra-operative samples were obtained in 106 patients (84.8%), which did not show any bacterial growth. A subacute periprosthetic infection occurred after seven months in only one patient. CONCLUSION: The results of the current study demonstrate that previously implanted osteosynthetic fixation devices do not significantly increase the risk of developing periprosthetic knee infections. A two-stage procedure with implant retrieval prior to total knee arthroplasty is not clinically indicated in the cohort described, amongst whom an infection rate of 0.9% was revealed.

Single-stage revision for peri-prosthetic shoulder infection: outcomes and results.

There have been only a few small studies of patients with an infected shoulder replacement treated with a single-stage exchange procedure. We retrospectively reviewed 35 patients (19 men and 16 women) with a peri-prosthetic infection of the shoulder who were treated in this way. A total of 26 were available for clinical examination; three had died, two were lost to follow-up and four patients had undergone revision surgery. The mean follow-up time was 4.7 years (1.1 to 13.25), with an infection-free survival of 94%. The organisms most commonly isolated intra-operatively were Staphylococcus epidermidis and Propionibacterium acnes; two patients developed a recurrent infection. Three different types of prosthesis were used: a hemiarthroplasty, a hemiarthroplasty with a bipolar head and reverse prosthesis. The mean Constant-Murley score at final follow-up was 43.3 (14 to 90) for patients with a hemiarthroplasty, 56 (40 to 88) for those with a hemiarthroplasty with a bipolar head and 61 (7 to 90) for those with a reverse prosthesis. The mean hospital stay was 10.6 days (5 to 29). Single-stage exchange is a successful and practical treatment for patients with peri-prosthetic infection of the shoulder.