Time to reconsider post arthroscopic osteonecrosis of the knee: a systematic review.

The etiology of post-arthroscopic osteonecrosis of the knee (PAONK) is still unknown. The aims of this systematic review were to analyze the main characteristics of patients who developed osteonecrosis after arthroscopy. We considered for inclusion in the review case reports, case series, retrospective and prospective clinical trial, that involved patients who developed osteonecrosis of the knee within 1 year of arthroscopy for meniscal lesion or anterior cruciate ligament rupture with or without chondropathy. In all cases, there was a pre-operative magnetic resonance imaging that excluded the presence of osteonecrosis. We used the MINORS criteria to estimate the risk of bias. A total of 13 studies that involved 125 patients were included in the review. Only 14 out of 55 patients performed the pre-operative MRI after the "window period", which we considered 6 weeks between the onset of symptoms and positive MRI findings. A diagnosis of PAONK was made for 55 patients within 1 year of surgery. Of these, 29% was treated conservatively, while 71% repeated surgery. Osteonecrosis after knee arthroscopy is a reality and surgeon shouldn't underestimate the persistence or re-emergence of symptoms after arthroscopy. It may be due to subchondral insufficiency fractures in osteopenic bone, without evidence of necrosis. However, there are not elements enough to differentiate clinical and radiological characteristics of PAONK from SPONK. Terminology should be simplified, distinguishing subchondral insufficiency fractures of the knee as a precursor of primary osteonecrosis of the knee.

Failure rate analysis and clinical outcomes of two different femoral tunnel positions using anteromedial portal technique in anterior cruciate ligament reconstruction.

AIM: To analyze two different femoral tunnel positions and to evaluate their correlation with clinical, functional outcomes and surgical revision rate in patients who underwent primary arthroscopic anterior cruciate ligament (ACL) reconstruction with anteromedial (AM) portal technique. METHODS: From January 2015 to October 2018, we recruited 244 patients that underwent primary single-bundle ACL reconstruction, using four strand-semitendinosus graft and AM portal technique for femoral tunnel placement. Patients were divided into two groups based on the different femoral tunnel positions: 117 patients of group A had ACL footprint center femoral tunnel position compared with 127 patients of group B, with femoral tunnel placement close to the AM bundle footprint. Preoperatively and at last follow up, all patients were assessed subjectively by Lysholm, Tegner, and International Knee Documentation Committee (IKDC) scores, while Lachman, Pivot-shift, and KT-1000 tests were performed to evaluate knee joint stability. RESULTS: Group B patients showed significantly better results in Lysholm, objective, and subjective IKDC scores compared with patients of group A (P < 0.001). A significantly higher surgical failure rate was found in group A than in group B (10.26% vs. 2.3%; P < 0.001). A higher anterior knee laxity was recorded in patients of group A than in patients of group B (1.9 ± 1.1 vs. 1.3 ± 1 mm; P < 0.001); a reduction in mean anterior tibial translation from preoperative to final follow up was found in group B compared with group A (3.5 ± 1.2 vs. 2.7 ± 1.1 mm; P < 0.001). No significant differences in the Tegner scale were found between the two groups. CONCLUSION: ACL reconstruction performed using the AM portal technique showed better and more satisfactory clinical and functional outcomes associated with a lower failure rate when the femoral tunnel had been placed more eccentrically in the footprint, in the AM bundle center position.

Allograft tendons are a safe and effective option for revision ACL reconstruction: a clinical review.

Revision anterior cruciate ligament reconstruction remains a challenge, especially optimising outcome for patients with a compromised knee where previous autogenous tissue has been used for reconstruction. Allograft tissue has become a recognized choice of graft for revision surgery but questions remain over the risks and benefits of such an option. Allograft tendons are a safe and effective option for revision ACL reconstruction with no higher risk of infection and equivalent failure rates compared to autografts provided that the tissue is not irradiated, or any irradiation is minimal. Best scenarios for use of allografts include revision surgery where further use of autografts could lead to high donor site morbidity, complex instability situations where additional structures may need reconstruction, and in those with clinical and radiologic signs of autologous tendon degeneration. A surgeon needs to be able to select the best option for the challenging knee facing revision ACL reconstruction, and in the light of current data, allograft tissue can be considered a suitable option to this purpose.Level of evidence IV.

Are contemporary femoral components sizing and design likely to affect functional results in TKA? A mathematical model of an implanted knee to predict knee forces.

PURPOSE: This study is aimed to investigate the effects of the choice of femoral and tibial components on several mechanical outputs that might be associated with total knee replacement surgery outcomes using a validated computational model: the Kansas knee simulator. METHODS: Two models from the same range of implants were taken into account: Model 1, the femoral component fitted the femoral epiphysis, with physiological positioning of the articulating surface using a 10-mm-thick tibial component, and in Model 2, the femoral component was 4 mm smaller than in Model 1, and a 14-mm-thick tibial component was used with a similar tibial resection and the tibio-femoral joint line was 4 mm more proximal to compensate the increased posterior bone resection and maintain proper soft-tissue tension in flexion. Changes in reaction forces and contact pressures between the components, changes in extensor muscle forces and changes in patello-femoral joint kinematics during walking gait have been studied. RESULTS: While the computational model predicted that most kinematic and kinetic outputs, including tibio-femoral and patello-femoral joint motions, contact forces, pressures and areas, were similar for Model 1 and Model 2, and a dramatic difference has been found in the extensor muscle forces necessary to flex and extend the knee. To reproduce the same knee motion with a knee reconstructed as in Model 2, a patient would need to generate approximately 40% greater extensor muscle force throughout the gait cycle in order to do so. CONCLUSION: As a consequence of such a large increase in the extensor muscle force, the knee motions would probably be compromised and, subsequently, a patient with a knee reconstructed as in Model 2 would be less likely to be able to reproduce normal knee function and therefore more likely to report poor outcome.

Complications during minimally invasive knee surgery.

Since their advent, minimally invasive surgical techniques have achieved good results in knee arthroplasty, earning the approval of many orthopaedic surgeons. The advantages offered by this type of surgery are the respect of the extensor system, early functional recovery and reduced pain. As always in surgery, in order to obtain such results, various problems have been tackled, some of which have now been overcome thanks to the new instruments that are better suited to restricted incisions, whereas others still cause significant complications. The excessive forces exercised on the soft tissues and patella can damage the tissues despite the less invasive incision. All the statistics provided by surgeons who most frequently use these techniques show complications due to the use of a minimally invasive technique that can be avoided with the standard techniques, which have given outstanding results for a long time. Above all, implantation accuracy appears to be reduced through a small incision. The highest complication rates are reported in the quadriceps-sparing technique, which does not allow a perfect view of the joint. In this review, we highlight the possible complications associated with this "new" surgical approach, which still requires further evolution in order to achieve the same results as the standard technique.

[Radiologic assessment of femoro-patellar instability. Personal experience and review of the literature]. / Valutazione radiologica dell'instabilità femoro-rotulea. Esperienza personale e revisione della letteratura.

PURPOSE: To propose a simple and reproducible radiological evaluation of patellofemoral instability to enable the orthopaedic surgeon to choose the best therapy. MATERIAL AND METHODS: We have evaluated retrospectively the radiographs and CT examinations of 25 patients, 15 female and 10 male, aged between 18 and 32 years. They underwent surgical treatment for patellar instability in the past 4 years. Lateral retinacular release has been performed in every patient, medial transposition of the anterior tibial tuberosity has been performed in 23 patients and in 5 of them also its distal replacement, proximal Insall's realignement was performed in 20 cases and only 1 patient underwent trochleoplasy. Preoperative conventional radiographs included antero-posterior view, true lateral view (exact superimposition of the posterior trochlear edges) and axial views at 30 degrees of knee flexion. On lateral view, the patellar height was evaluated based on Caton-Deshamps index and trochlear dysplasia assessed using the methods suggested by Dejour. A CT examination of both knees was performed: the images were taken first with knees in extension, with and without quadriceps contraction, then in flexion at 20 degrees. Patellar "bascùle" angles were measured both with quadriceps relaxed and contracted as an index of quadriceps dysplasia; the TAGT in extension was evaluated as an index of the degree of lateral position of the anterior tibial tuberosity. Preoperative conventional and CT findings were compared with those obtained postoperatively at 30.4 months from the surgical intervention. RESULTS: All patients were free from complaints after surgery. In 5 patients a high patella was corrected by distal realignement of anterior tibial tuberosity. A trochlear dysplasia with different degrees of severity was present in all cases and it was not modified by surgical treatment, with the exception of the patient who underwent trochleoplasty. In the 20 patients who underwent proximal Insall's realignment, patellar "bascùle" angles--pathological before surgery--were restored to normal values with the exception of 3 cases. In 23 patients who underwent medial transposition of anterior tibial tuberosity, the values of the TAGT were all normalized: nevertheless, in three patients low values of the TAGT were found after surgery and this condition may predispose to the development of medial patellofemoral by iperpression syndrome. CONCLUSIONS: In patients suffering from patellofemoral instability, a radiological protocol which includes conventional radiographs in two projections and a CT examination both in extension, with and without quadriceps contraction, and in flexion at 20 degrees supplies all the information needed for evaluating patellar height and mobility, trochlear dysplasia, valgism of the knee and the degree of excessive lateral position of the anterior tibial tuberosity. Careful evaluation of such abnormalities is important for selecting the best surgical treatment for each patient. It's a simple, quick, and accurate protocol that may be reproduced, even using different radiographic equipment. The collaboration between the radiologist and the orthopaedic surgeon is crucial for the correct interpretation of radiological findings, which must be evaluated together with clinical findings so that an adequate therapeutical plan could be proposed.

[Shoulder diseases in throwing athletes: radiologic assessment and surgical correlation]. / Patologie della spalla del lanciatore: valutazione radiologica e correlazioni chirurgiche.

Lesions of the shoulder, especially rotator cuff tears and glenoid labrum (SLAP) lesions, are commonly caused by traumatic episodes in athletes such as repeated trauma from throwing. The available radiological methods are MRI, CT and MR arthrography. Twelve athletes suffering from shoulder pain or instability have been studied and then underwent successful treatment in arthroscopy. On the basis of our results and experience, we think that MR, especially with intra-articular injection of contrast medium, is the best examination because it offers an accurate evaluation of both rotator cuff and glenoid labrum. Nevertheless difficulties are often encountered and definitive diagnosis sometime rests on arthroscopic exploration.

[Shoulder instability: diagnostic imaging]. / Instabilità di spalla: diagnostica per immagini.

Shoulder instability is often diagnosed among athletes; two clinical forms are distinguished: anatomical instability, with recurrent luxation of the shoulder, and functional instability, with pain, articular "click" and sensation of instability. Lesions of periarticular soft tissues (capsula, fibrocartilaginous labrum, gleno-humeral ligaments and rotator cuff) are common in both forms, while lesions of bone structures (humeral head and glenoid of scapula) are typical of shoulder with previous dislocation. Purpose of our retrospective study was to verify the value of magnetic resonance (MRI) and computed arthrography (arthro-CT) in diagnosing these lesions in 57 patients suffering from shoulder instability. On the basis of our results and experience we think that in a preoperative evaluation of an unstable shoulder, arthro-CT and arthro-MRI are more accurate because the intra-articular injection of a contrast medium better identifies lesions of capsula, gleno-humeral ligaments and fibrocartilaginous labrum. In other circumstances, such as the study of the shoulder for legal purposes, MRI is preferable because it offers an accurate and global evaluation of periarticular structures.

[Injuries of the cruciate ligament of the knee: diagnostic contribution of MR and spiral CT]. / Lesioni dei legamenti crociati del ginocchio: contributo diagnostico della RM e della spiral-TC.

Lesions of cruciate ligament are common after knee trauma of different degree of gravity. Lesions evaluation is possible thanks to CT and MRI. Our purpose is to verify their value in diagnosis of cruciate ligaments lesions. We retrospectively evaluated 160 patients (80 CT and 80 MRI) with subsequent diagnosis of cruciate ligaments injury. CT and MRI were performed in the acute phase and in the subacute phase within 2-3 weeks from trauma. On the basis of our results CT and MRI shown a reduced sensitivity in acute phase owing to the intraarticular haemorrhage; in this phase MRI gives more information about fibres interruption. In subacute or chronic phase, both methods are correct in recognising the lesions but MRI is more sensitive and accurate. It is a real wish that, with more MRI machines diffusion, this method will be preferred in the study of cruciate ligaments both in acute phase and subacute-chronic phase.

Subcapital fractures of the femur. Treatment by reduction and fixation and 3 spongy bone screws.

The authors reviewed 21 cases of subcapital fracture of the femur treated by reduction and fixation with 3 spongy bone screws (AO type) between 1980 and 1983. There were 4 failures (2 non-union and 2 ischaemic necrosis, one definite and one suspected). In all patients with a reasonable life expectancy the treatment should be reduction and fixation, but the technique must be extremely accurate. If open reduction is necessary to ensure perfect reduction, it must be by the anterior route so as not to inflict further damage on the blood supply. Fixation must be rigid and sustained. This can be best achieved by using 3 screws of the AO spongy type which also ensures a degree of compression which enhances consolidation.