Epiphyseal fixation in revision total knee arthroplasty: a comparison between trabecular metal and titanium augments.

INTRODUCTION: The purpose of this retrospective study was to compare the medium-term clinical and radiographic outcomes of two series of patients treated for revision TKA: one implanted with trabecular metal (TM) augments and one implanted with classic titanium augments. MATERIALS AND METHODS: A total of 85 patients with a type 2 AORI defect underwent revision TKA and were treated either with TM epiphyseal augments directly screwed in the bone or with traditional titanium augments. There were 46 patients in the TM group and 39 patients in the titanium group included in the study. All the patients received the same varus-valgus constrained implant and no metaphyseal fixation devices were used. RESULTS: After a mean follow-up of 66.4 months, no statistically significant difference was observed in terms of failure for aseptic loosening between the two groups (4% in the TM group and 7.8% in the titanium group, p = 0.35). The ten-year survival using aseptic loosening as endpoint was 90.5% (95% CI 94.1-98.6) in the TM group and 85% (95% CI 101.9-119.3) in the titanium group (p = 0.26). A statistically significant difference was detected for the presence of RLL. No RLL were found under the studied TM augments compared to 13.7% of the titanium augments (p = 0.01). CONCLUSION: The use of TM augments directly screwed to the epiphysis of the femur and the tibia reduced the incidence of RLL compared to standard titanium augments during revision TKA with promising medium-term results.

The flexion space is more reliably balanced when using the transepicondylar axis as compared to the posterior condylar line.

PURPOSE: The purpose of this study was to evaluate the differences in flexion space balance when the femoral component is implanted parallel to the surgical transepicondylar axis (TEA) or with 3° of external rotation from the posterior condylar line (PoCoLi). It was hypothesized that implantation parallel to the TEA will produce a more reliably balanced flexion space. METHODS: Forty-eight consecutive patients with a varus deformity were prospectively randomized to undergo total knee arthroplasty with a femoral component implanted parallel the TEA, or with 3° of external rotation from the PoCoLi. The posterior condylar angle (PCA) was measured. Intraoperative load measurements were taken at 10°, 45°, and 90° of flexion. RESULTS: The PCA was similar between groups (TEA group: 4.2° ± 1.5° and PoCoLi group: 4.0° ± 1.3°; n.s.). The mean difference in load values between the medial and lateral compartments was significantly lower in the TEA group than in the PoCoLi group at the 45 (0 ± 8 vs. 9 ± 13 lbs; respectively, p = 0.008) and 90° flexion angles (1 ± 9 vs. 10 ± 15 lbs; respectively, p = 0.01). The PoCoLi group had a linear increase in the difference of load values between the medial and lateral compartments with increasing magnitude of the posterior condylar angle (45°, p = 0.0013; 90°, p = 0.0006), but this was not observed in the TEA group. CONCLUSION: Femoral component implantation parallel to the TEA resulted in a more balanced flexion gap as compared to implantation at 3° of external rotation from the PoCoLi. The intraoperative use of the TEA rather than the PoCoLi to set femoral component rotation may provide a more balanced flexion space and decrease the need for extensive soft tissue releases. LEVEL OF EVIDENCE: II.

High performance of α-defensin lateral flow assay (Synovasure) in the diagnosis of chronic knee prosthetic infections.

PURPOSE: This prospective study was undertaken to evaluate the diagnostic accuracy of the Synovasure™ α-defensin lateral flow assay to detect or exclude infection and to compare it to the sensitivity and specificity of other diagnostic criteria according to the International Consensus Group on Periprosthetic Joint Infection (PJI). METHODS: All patients who have undergone revision total knee arthroplasty (TKA) from September 2015 to July 2016 were included: 16 chronic (more than 3 months after performing arthroplasty) infections and 35 aseptic joints were identified. The diagnostic performance of single test was assessed by receiver operating characteristic (ROC) curve analyses. The sensitivity and specificity were calculated for each of the cut-off values and the area under the curve (AUC) was also calculated. RESULTS: The median synovial fluid (SF) leukocyte count, as well as the neutrophil percentage, was significantly higher in patients with PJI than in those with aseptic failure (p < 0.001). The sensitivity of α-defensin was 87.5% (95%; CI 74.6-94.7), the specificity was 97.1% (95% CI 86.9-99.7), the positive predictive value 93.3% (95% CI 81.8-98.1), and negative predictive value was 94.4% (95% CI 83.2-98.6). The results in terms of sensitivity and negative predictive value were greater than those of the other tests (cultures, synovial cell count, erythrocyte sedimentation rate, and C-reactive protein). The diagnostic accuracy of α-defensin, with an area under the curve of 0.92, was found to be higher than all the minor criteria for PJI. CONCLUSIONS: In this study, the α-defensin lateral flow test was found to have the highest performance of all tests studied to identify PJI. Synovasure™ holds the potential to be included in the daily clinical practice. LEVEL OF EVIDENCE: Level I diagnostic study.

Diagnostic accuracy of synovial fluid, blood markers, and microbiological testing in chronic knee prosthetic infections.

INTRODUCTION: This retrospective study was undertaken to define cut-off values for synovial fluid (SF) leukocyte count and neutrophil percentage for differentiating aseptic failure and periprosthetic joint infection (PJI) and to evaluate the diagnostic accuracy of blood inflammatory markers, and microbiological testing according to the criteria proposed by the International Consensus Meeting (ICM) of Philadelphia. METHODS: All patients who underwent revision total knee arthroplasty from January 2010 to July 2015 were included: we identified and classified 31 PJIs and 136 aseptic joints. The diagnostic performance of single test was assessed by receiver operating characteristic curve analyses. The sensitivity and specificity were calculated for each of the cut-off values and the area under the curve (AUC) was calculated. RESULTS: The median SF leukocyte count as well as the neutrophil percentage and inflammatory markers were significantly higher in patients with PJI than in those with aseptic failure (p < 0.001). A leukocyte count of > 2.8 × 103/µL had a sensitivity of 83.8% and a specificity of 89.7% whereas a neutrophil percentage of > 72% yielded a marginally higher sensitivity of 84% and a specificity of 91%. Applying the ICM criteria we found a significant correlation between all these diagnostic measures and PJI (p < 0.001) except for a single positive culture. The most accurate criterion of the ICM was the synovial neutrophil differential (AUC = 0.89; 95% CI 0.81-0.97), followed by SF leukocyte count (AUC = 0.86; 95% CI 0.78-0.94), increased inflammatory markers (AUC = 0.85; 95% CI 0.76-0.93), and two positive periprosthetic cultures (AUC = 0.84; 95% CI 0.73-0.94). The presence of sinus tract communicating with the joint and a single positive culture showed unfavourable diagnostic accuracy (AUC = 0.60, 95% CI 0.47-0.72; AUC = 0.49, 95% CI 0.38-0.61, respectively) CONCLUSIONS: The present study highlights the adequate ability of fluid cell count and neutrophil differential to distinguish between PJI and aseptic loosening. The clinical utility of fluid analysis in diagnosing infection can be improved by evaluation of other diagnostic criteria. LEVEL OF EVIDENCE: Level I Diagnostic Study.

Intraoperative Load-Sensing Variability During Cemented, Posterior-Stabilized Total Knee Arthroplasty.

BACKGROUND: Load-sensing technology during total knee arthroplasty (TKA) provides objective measurements of ligamentous balance. The purpose of this study is to assess its intraoperative validity and reliability during TKA. METHODS: Fifty-four patients underwent TKA using the OrthoSensor VERASENSE tibial insert to assist with ligament balance. The transepicondylar axis (TEA) was used to determine femoral component rotation, and the posterior condylar angle (PCA) was measured. Load measurements were documented at 10°, 45°, and 90° of flexion with the trial (TRIAL) components and with the definitive (FINAL) cemented implants. Adequate balance was defined as a load differential ≤15 pounds between compartments. RESULTS: Adequate balanced with TRIAL and FINAL implants was observed in 89% TKAs. There was a significant linear correlation of the TRIAL and FINAL loads in the medial compartment throughout range of motion. No correlation between the TRIAL and FINAL loads was identified in the lateral compartment. There was no relationship between an increasing PCA and medial compartment loads at 45° (R2 = 0.0006, Y = -0.10X + 7.3 ± 2.3; P = .86) and 90° (R2 = 0.004, Y = -0.25X + 6.3 ± 2.1; P = .62) of flexion, suggesting that the compartment loads were not significantly altered with femoral rotation parallel to the TEA. A similar finding was observed in the lateral compartment at all poses. CONCLUSION: Variability between the TRIAL and FINAL implant measurements was higher in the lateral compartment as compared to the medial compartment. Using the TEA and not the posterior condylar line as a landmark to guide femoral component rotation, the flexion gap is frequently balanced without the need for additional ligament releases.

The role of tendon and subacromial bursa in rotator cuff tear pain: a clinical and histopathological study.

PURPOSE: To evaluate a possible association of shoulder pain with the clinical features and the histopathological changes occurring in the ruptured tendon and subacromial bursa of patients with rotator cuff tear. METHODS: One hundred and eighty patients were clinically evaluated with the constant score and the visual analogue pain scale. Radiographs and MRI were performed. The chronology of the rupture, the muscle fatty degeneration according to Goutallier's scale and the tear size were evaluated. For each patient, a biopsy of the supraspinatus tendon and subacromial bursa was performed during arthroscopic rotator cuff tear repair and the specimens were histopathologically analysed. RESULTS: Clinically, the shoulder was more painful in females, in the presence of a chronic cuff lesion and a low Goutallier's grade (P < 0.05). No association was found between pain and age of the patient and between pain and tear size. Histologically, hypertrophy and inflammation of the tendon and hypertrophy, inflammation, oedema and necrosis of the subacromial bursa were directly associated with pain (P < 0.05). Pain decreased significantly in the presence of fatty metaplasia and necrosis of the tendon (P < 0.05). CONCLUSIONS: This study defines the main clinical and histopathological features of painful rotator cuff tear. In particular, a greater association of pain was observed with the histopathological changes in the bursa compared with those in the rotator cuff. Considering that the bursa plays also an essential role during the healing process, this "new" role of the subacromial bursa as pain generator has important repercussions in both pharmacological and surgical treatments of rotator cuff tears. LEVEL OF EVIDENCE: IV.

Femoral Component Rotation in Total Knee Arthroplasty: A Comparison Between Transepicondylar Axis and Posterior Condylar Line Referencing.

BACKGROUND: Proper rotational alignment of the femoral component is critical for a successful total knee arthroplasty (TKA). Controversy remains regarding the optimal intraoperative reference to determine femoral component rotation. METHODS: Thirty-one patients who underwent magnetic resonance imaging of a TKA between April 2008 and November 2015 were retrospectively reviewed. A single surgeon performed the TKA using a posterior condylar angle of 3° (PCA group) or surgical transepicondylar axis (TEA group) to determine femoral component rotation. The hip-knee-ankle angle and the tibial plateau-tibial shaft angle (TPTSA) were measured on full-length x-rays, and the rotation of the femoral component was measured as compared to the TEA on magnetic resonance imaging (negative values indicate internal rotation). RESULTS: The median measured rotational deviation of the femoral component from the TEA was significantly higher in the PCA group than in the TEA group (-3.8 ± 2.9° and -1.4 ± 1.9°, respectively) (P = .02). When knees with preoperative varus and neutral alignment were evaluated, the median measured rotational deviation of the femoral component was significantly higher in the fixed PCL group than in the TEA group (-3.4 ± 3.3° and -0.61 ± 1.3°, respectively) (P = .04). Linear regression used to evaluate the relationship between the TPTSA and femoral component rotational deviation from the TEA revealed similar near zero slopes (P = .90); however, the Y intercepts in the TEA group were significantly higher than the PCA group (-2.8 ± 0.7 and -5.5 ± 1.1, respectively) (P = .007). CONCLUSION: The use of the surgical TEA as an intraoperative rotational reference is more reliable than the PCA in valgus, varus, and neutrally aligned knees independent from the magnitude of the TPTSA.

The role of offset stems in revision knee arthroplasty.

Revision total knee arthroplasty (TKA) represents a technically challenging procedure. The use of an offset stem extension can help in addressing some of the difficulties that can be encountered during surgery and, in particular, anatomical mismatch, malalignment, and gap balancing. Different offset stem extensions are available and can be classified according to four parameters: modularity, location of the offset, direction, and size of the displacement. Offset stem extensions can assist with implant alignment on the metaphysis if there is an offset diaphysis, can avoid medial-lateral or anterior-posterior component overhang, can reduce the incidence of coronal or sagittal malalignment, and can help in balancing the flexion and extension spaces by effectively translating the components. The aim of this study is to give an overview of the currently available evidence regarding the use of offset stem extensions in revision TKA as well as some useful surgical tips.

Tendon transfer for irreparable rotator cuff tears: indications and surgical rationale.

BACKGROUND: treatment of symptomatic irreparable rotator cuff tears is extremely challenging because, at present, there are no ideal solutions to this problem. Many patients respond favorably to nonsurgical treatment. However, when conservative measures fail to improve the patient's pain and disability, surgery should be considered. METHODS: different surgical techniques are available and the choice of the most appropriate procedure depends on the presenting symptoms, age of the patient, functional demand, medical comorbidities, joint stability and presence of arthritic changes. The transposition of the surrounding muscles to replace the rotator cuff function represents a viable option in the treatment of younger patients without glenohumeral osteoarthritis and with severe functional limitation. PURPOSE: aim of this study is to give an overview of the currently available evidence regarding tendon transfer procedures for irreparable rotator cuff tears.

Shoulder osteoarthritis.

Osteoarthritis (OA) is the most frequent cause of disability in the USA, affecting up to 32.8% of patients over the age of sixty. Treatment of shoulder OA is often controversial and includes both nonoperative and surgical modalities. Nonoperative modalities should be utilized before operative treatment is considered, particularly for patients with mild-to-moderate OA or when pain and functional limitations are modest despite more advanced radiographic changes. If conservative options fail, surgical treatment should be considered. Although different surgical procedures are available, as in other joints affected by severe OA, the most effective treatment is joint arthroplasty. The aim of this work is to give an overview of the currently available treatments of shoulder OA.

Periprosthetic shoulder infection.

Shoulder arthroplasty is considered the most effective surgical procedure for endstage shoulder pain from different causes including osteoarthritis, cuff-tear arthropathy, trauma, and tumors. Although uncommon and less frequent than knee or hip periprosthetic infection, periprosthetic shoulder infection represents a devastating complication and, despite treatment, is associated with unsatisfactory results. The most commonly identified microorganisms in periprosthetic shoulder infections are Staphylococcus aureus, coagulase-negative Staphylococci and Propionibacterium acnes. Diagnosis is not always easy and mainly derives from the integration of clinical symptoms, laboratory exams, radiological studies and microbiological swabs. Different options are available for treatment, including antibiotic therapy, lavage and debridement with retention of the prosthesis, one-stage reimplantation, two-stage reimplantation with antibiotic-impregnated cement spacer and resection arthroplasty. The aim of this review is to describe the current knowledge regarding risk factors, etiology, diagnosis and treatment of periprosthetic shoulder infection.

Patellar osteoid osteoma as a cause of anterior knee pain in adolescents: a case report and literature review.

Anterior Knee Pain (AKP) is an important cause of complaint in adolescents which can suggest many possible diseases. Scientific literature concerning this complex symptom is wide and diversified. We report a rare case of patellar osteoid osteoma which affected a thirteen-year-old female who had suffered from anterior left knee pain for almost six months. The diagnosis was suspected from an accurate anamnesis, a careful clinical examination, and confirmed by imaging. Several minimally invasive techniques can be employed to treat osteoid osteoma. However, we consider CT-guided percutaneous drilling the safest and most effective procedure in case of patellar location. Despite its rarity, patellar osteoid osteoma ranges in the differential diagnosis for all patients suffering from AKP.

Osteochondroma as a cause of scapular winging in an adolescent: a case report and review of the literature.

INTRODUCTION: Winged scapula is defined as the prominence of the medial border of the scapula. The classic etiopathology of scapular winging are injuries to the spinal accessory or long thoracic nerves resulting respectively in trapezius and serratus anterior palsy. To the best of our knowledge, there are only few reports of scapular lesions being mistaken for winging of the scapula. We report a rare case of a large scapular osteochondroma arising from the medial border and causing a pseudowinging of the scapula. CASE PRESENTATION: A 17-year-old Caucasian boy came to us complaining about a winged left scapula. The patient had a complete painless range of motion, but a large hard bony swelling was palpable along the medial border of his left scapula. A grating sensation was felt when his arm was passively abducted and/or elevated causing discomfort. A lesion revealed on X-rays was diagnosed as an osteochondroma of the medial border of his scapula. After preoperative examinations, he underwent open surgery in order to remove the lesion. A histological examination confirmed the clinical diagnosis of osteochondroma. A clinical examination 3 months later showed a full and painless range of motion, the absence of the grating sensation during passive abduction and elevation and the complete disappearance of his left shoulder deformity. After 2 years of follow-up, there were no clinical or radiological signs of recurrence. CONCLUSIONS: Despite its rarity osteochondroma should be considered in the differential diagnosis for any adolescent presenting with a winging of the scapula.

Epidemiology of isolated acromioclavicular joint dislocation.

Background. Acromioclavicular (AC) joint dislocation is a common shoulder problem. However, information about the basic epidemiological features of this condition is scarce. The aim of this study is to analyze the epidemiology of isolated AC dislocation in an urban population. Materials and Methods. A retrospective database search was performed to identify all patients with an AC dislocation over a 5-year period. Gender, age, affected side and traumatic mechanism were taken into account. X-rays were reviewed by two of the authors and dislocations were classified according to the Rockwood's criteria. Results. A total of 108 patients, with a mean age of 37.5 years were diagnosed with AC dislocation. 105 (97.2%) had an isolated AC dislocation, and 3 (2.8%) were associated with a clavicle fracture. The estimated incidence was 1.8 per 10000 inhabitants per year and the male-female ratio was 8.5 : 1. 50.5% of all dislocations occurred in individuals between the ages of 20 and 39 years. The most common traumatic mechanism was sport injury and the most common type of dislocation was Rockwood type III. Conclusions. Age between 20 and 39 years and male sex represent significant demographic risk factors for AC dislocation.