Optimised fast-track protocols in total knee arthroplasty determine shorter hospitalisation time and lower perioperative/postoperative complications.

PURPOSE: This literature review aims to present evidence-based clinical recommendations for the eight most debated topics related to perioperative management in total knee arthroplasty: counselling, prehabilitation, transfusion risk, tranexamic acid, drainage, analgesia, urinary catheter and compression stockings. METHODS: A multidisciplinary team conducted a systematic review on these topics. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for the literature review and result presentation. The research encompassed articles from 1 January 2009 to 28 February 2023, retrieved through the MEDLINE database via PubMed, Embase database and Cochrane Library. RESULTS: Forty-five articles were selected. Preoperative counselling has limited evidence for its impact on postoperative outcomes; yet, it can help alleviate surgery-related anxiety and manage postoperative symptoms. Prehabilitation can also prepare patients for surgery, reducing hospital stays and improving postsurgery functionality. Numerous studies suggest that preoperative Hb levels are independently linked to transfusion risk, with a recommended level of 13 g/dL. Combining intravenous and local tranexamic acid administration is strongly advised to reduce perioperative blood loss, while drainage after primary total knee arthroplasty offers no functional advantages. Employing a multimodal analgesia approach yields better results with reduced opioid usage. Indwelling urinary catheters provide no benefit and avoiding them can lower the risk of urinary tract infections. As for compression stockings, there is insufficient evidence in the literature to support their efficacy in preventing venous thromboembolism. CONCLUSION: The best-track protocol has demonstrated its efficacy in reducing hospitalisation time and perioperative/postoperative complications. It is success relies on a collaborative, resource-adaptive approach led by a multidisciplinary team. Both patients and hospitals benefit from this approach, as it enhances care quality and lowers costs. Several studies have highlighted the significance of a patient-centred approach in achieving high-quality care. Creating a novel treatment protocol could be a prospective goal in the near future. LEVEL OF EVIDENCE: Level III.

The meniscal extrusion index is a reliable indirect sign of different meniscal lesion patterns: a classification based on percentage of meniscal extrusion.

PURPOSE: This study's goal is to propose a straightforward classification system based on the MEI (Meniscal Extrusion Index), a measure of meniscal extrusion, that relates to various meniscal lesion patterns and has clinical and biomechanical significance. The study's secondary goal is to determine whether the standard 3 mm meniscal extrusion parameter still has value by correlating the MEI with it. METHODS: 1350 knee MRIs that were performed over the course of 2 years made up the study cohort. Following the application of inclusion and exclusion criteria, 200 of those patients were qualified to participate in the study. All the measurements examined for this study underwent an interobserver reliability test. RESULTS: In the 1350 MRIs that were examined for this study, meniscal extrusion of any grade was present 18.9% of the time. The use of the MEI revealed three groups of patients: those with a MEI < 20%, who are likely para-physiological; those with a MEY between 20% and 40%, who are in a grey area; and those with a MEY > 40%, who have lesions that are impairing the proper meniscal function. According to the authors' findings, the percentage of meniscal extrusion did not correlate with the finite number (3 mm), making the 3 mm parameter an unreliable evaluation method. CONCLUSIONS: This study is clinically relevant, because it proposes a simple and reproducible classification of meniscal extrusion that may aid in evaluating the severity of an extrusion and help in the diagnosis of lesions that might be difficult to identify on MRI. LEVEL OF EVIDENCE: Level IV.

Efficacy of Subchondroplasty in the Treatment of Pain Associated With Bone Marrow Lesions in the Osteoarthritic Knee.

Background: Bone marrow lesions (BMLs) are common subchondral defects revealed by magnetic resonance imaging (MRI) in patients with osteoarthritis, often associated with pain and functional limitation. Subchondroplasty (SCP) is a relatively new technique in which bone substitute material (BSM) is injected inside BML areas to provide structural support to the subchondral bone, preventing its collapse and reducing pain. Purpose/Hypothesis: The purpose of this study was to characterize changes in pain, functional and radiological outcomes, conversion to knee replacement, and complications after SCP. We hypothesized that ≥70% of patients would achieve a reduction in pain of ≥4 points on a numeric rating scale (NRS) at a 6-month follow-up after SCP. Study Design: Case series; Level of evidence, 4. Methods: Patients with symptomatic knee BMLs who underwent SCP were prospectively evaluated preoperatively and at 1, 6, 12, and 24 months postoperatively. Functional outcomes were measured with the NRS for pain, Knee Society Score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and International Knee Documentation Committee (IKDC) scores. Radiographs and MRI were performed preoperatively and at 6- and 12-month follow-ups to verify edema healing and changes in bone structure. Results: A total of 50 patients were included in the study. The mean follow-up was 26 months (24-30 months). Compared with preoperative values, the mean NRS score decreased at every follow-up point (P < .0001 for all) and the IKDC, WOMAC, and KSS scores improved significantly at 6- and 12-month follow-ups. At 6 months postoperatively, 27 patients (54%) registered a reduction on the NRS of ≥4 points. Postoperative MRI revealed a hypointense zone surrounded by a hyperintense signal at the injection site. Standard radiography showed osteoarthritis grade worsening in 4 (8%) patients. Knee replacement was performed in 11 patients -in 7 patients due to the worsening or persistence of disabling symptoms and in 4 patients due to the progression of osteoarthritis. The leakage of BSM occurred in 6 patients without any clinical consequences during the study period. Conclusion: About half of the study patients achieved a reduction in the NRS of 4 points at the 6-month follow-up after SCP. Registration: NCT04905394 (ClinicalTrials.gov identifier).

Bone marrow lesions in the knee are associated with meniscal lesions and cartilage pathologies according to the six-letter system.

PURPOSE: This study aims to find a correlation between bone marrow lesions (BMLs) in knee MRI and pathologies of joint structures. In addition, according to the six-letter system classification, the authors analyzed a potential association between the area affected by BMLs and the specific type of joint lesion. METHODS: The authors screened all the knee MRIs performed in the investigation center between 2017 and 2018 to identify the presence of BMLs. The lesions were then categorized following the "six-letter system". The authors searched the presence of associated meniscal, chondral or ligamentous lesions. Finally, the authors researched a correlation between the lesion type described by the six-letter system classification and the associated lesions. RESULTS: MRI exams of 4000 patients were studied, identifying 666 BMLs. The associated lesions were collected for all patients, resulting in an overall prevalence of related lesions in almost 90% of patients. The authors found a statistical significance for type TLD (Tibia-Lateral-Articular) and ACL rupture. The study suggests a strong positive correlation between type E (Edge) and meniscal fracture or extrusion. CONCLUSION: BMLs in the knee are associated in 90% of cases with a radiological sign of related injury to the joint structures. The six-letter system of BMLs type TLD can be considered a sign of ACL rupture and type E as a high suspicious sign for meniscal extrusion. Those very typical BML patterns can help the clinician in the diagnosis of ACL tears and meniscal extrusion. Furthermore, the presence of a BML must be, for the clinician, a high suspicious sign of joint-related injuries. LEVEL OF EVIDENCE: Level 1.

Good patient satisfaction with low complications rate after trochleoplasty in patellofemoral instability.

PURPOSE: Trochlear dysplasia has been recognized as the most common factor in patients with patellofemoral dislocation. Trochleoplasty is a surgical procedure whose primary goal is to modify the femoral trochlea's abnormal shape in patients suffering from patellar instability, requiring good surgical skills, correct indication, and accurate patient information. METHODS: The review aims to describe preoperative planning, patient selection, most common surgical techniques, and clinical results of trochleoplasty in patellar instability in a reproducible manner. RESULTS: Trochleoplasty can be considered a general term to describe a group of different procedures that reduce trochlear dysplasia's impact on patellar instability, aiming to restore patella-trochlear congruency, remove the supratrochlear bump, allowed a new groove positioning and are generally associated with other procedures. Recent studies showed satisfactory long-term results with the restoration of patellar stability, improving radiological findings of patellofemoral instability. CONCLUSION: Trochleoplasty is a technically demanding technique, requiring careful patient selection, detailed knowledge, and surgical skills to avoid severe complications. Good patient satisfaction with a low risk of significant complications such as patellofemoral arthritis has been revealed. In conclusion, trochleoplasty should be systematically included in the treatment of patellar dislocation, if indicated. LEVEL OF EVIDENCE: V.

Management of a rare intra-articular fracture of the lateral femoral condyle: case report.

Unicondylar fractures of the femur are uncommon injuries that can occur in the sagittal or, less frequently, in the coronal plane (Hoffa fractures).  Distal femoral fractures are usually described following the AO/OTA Classification system which includes extra-articular, partial articular and intra-articular injuries, further divided in three types based on the pattern and comminution.  Accurate reduction and stable fixation are needed especially in articular injuries in order to allow early mobilization and reduce complications such as knee stiffness, malunion or secondary osteoarthritis. The aim of this paper is to report a case of an unusual articular fracture of the lateral femoral condyle in a 39 years old man. This fracture reminds the pattern of a typical tibial plateau injury, not embedded in the most common descriptions of femoral traumas. Indeed, in most cases, high energy traumas in valgus of the knee result in a damage to the tibial plateau because of the condyles impact on the tibial articular surface, while in the present case the opposite occurred. The patient was successfully treated with an open reduction and fixation with two cannulated leg screws, reporting  good clinical outcome and excellent healing of the fragment evidenced with CT scan at 6 months follow-up.

Arthroscopic-assisted reduction and fixation of proximal tibial fractures: personal surgical technique.

Purpose The purpose of this study was to describe the authors' arthroscopic-assisted reduction and fixation (ARIF) technique in the treatment of type Schatzker I-III tibial plateau fractures, with the use of instruments commonly used in anterior cruciate ligament reconstruction, evaluating clinical and radiological outcomes on four patients at short-term follow-up.   Methods A retrospective analysis was performed in our Institution considering 4 patients who underwent ARIF procedure between 2018 and 2020 at minimum 3 months of follow-up. All patients were evaluated clinically (Rasmussen Score, VAS and Crosby-Insall Grading) and radiographically (after surgery and at 6 weeks).   Results Mean follow-up was 9 months (range 6-12 months). Rasmussen score and VAS were respectively 26 (Excellent) and 1 at the last follow-up. According to the Crosby-Insall Grading System, all patients reported excellent results. At final control the mean ROM in the injured knee was 125°(range 100°-140°). Mean hospitalization was 2 days (range 1-4 days). No adverse events were reported.   Conclusions ARIF  is a reliable technique for tibial plateau fracture (Schatzker I-III). The technique described is very cheap and reproducible in any hospital . This procedure allows to well understand the pattern of fracture and to obtain an anatomical reduction with a great tissue sparing and a faster recovery of knee function.   Level of Evidence: Level IV   Keywords: tibial plateau fractures, treatment, arthroscopy, surgery, artrhoscopic-assisted.

The Evaluation of Trochlear Osseous Morphology: An Epidemiologic Study.

BACKGROUND: The femoral trochlea is considered the most significant osseous factor affecting stability in the patellofemoral joint. The true prevalence of trochlear dysplasia in the general population is largely unknown. PURPOSE/HYPOTHESIS: To investigate the prevalence of trochlear dysplasia in the general population. Our hypothesis was that, while trochlear dysplasia is not uncommon, there is a low prevalence of severe dysplasia in the general population. STUDY DESIGN: Descriptive epidemiology study. METHODS: Five observers were asked to evaluate 692 skeletally mature femoral specimens from 359 skeletons for trochlear dysplasia at 2 time points. We further subclassified the dysplastic trochlea in 62 femora with the highest rated degree of dysplasia. RESULTS: Sex (P = .11) and race (P = .2) had no effect on the severity of dysplasia. Interobserver reliability was excellent (0.906 and 0.904), and intraobserver reliability was good to excellent (0.686 to 0.808). The percentages of trochlea graded as normal, mildly dysplastic, moderately dysplastic, and severely dysplastic were 61.5%, 21.4%, 12.7%, and 4.4%, respectively, in the first evaluation, and 58.5%, 23.7%, 12.7%, and 5.1% in the second evaluation. Of the 62 trochlea with the highest scores for dysplasia, 36 had trochlear dysplasia without a supratrochlear spur, 8 had trochlear dysplasia with medial femoral condyle hypoplasia, and 18 had trochlear dysplasia with a supratrochlear spur. CONCLUSION: Observers with differing degrees of clinical experience had similar opinions on the degree of trochlear dysplasia. Also, our cohort showed that moderate to severe dysplasia is not uncommon, as it is present in approximately 17% of knees in our cohort. Our findings also suggest that clinicians are speaking the same language when identifying and describing trochlear dysplasia on gross inspection.

Validation of a new topographic classification of bone marrow lesions in the knee: the six-letter system.

PURPOSE: The aim of this study was to propose and validate a new six-item topographical classification of knee bone marrow lesions in coronal MRI images, to provide an easy-to-use aid to describe their location in a more reproducible and accurate way. METHODS: This study was conducted in four phases. The first was to do a literature search for methods of describing bone marrow lesions in MRI of the knee. The second was creation of a six-area topographic classification of bone marrow lesions in coronal MRI of the knee. The third phase was selection of cases with bone marrow lesions on knee MRI performed in a single hospital between January of 2017 and December of 2018. The fourth phase was categorization of the bone marrow lesions' location according to the new proposed classification by three independent examiners, two orthopedic surgeons and one radiologist. Patient's demographic data and associated lesions were collected. The inter-observer and intra-observer reliability of the proposed classification was then calculated. RESULTS: MRI examination of 4000 patients were studied and in 520 patients a total of 666 bone marrow lesions were identified and their location classified using the new system. The inter-observer and intra-observer reliability analysis found a Fleiss' Kappa value of 0.96 (0.95-0.97) and 0.97 (0.96-0.97), respectively, confirming the high reproducibility of the proposed classification. CONCLUSIONS: The proposed six-location classification of bone marrow lesions is highly reproducible and can help researchers develop studies and share information in a more accurate and reliable way. The correct classification of bone marrow lesions can lead to a more accurate description of this pathology and help clinicians to propose appropriate therapies for this group of patients. LEVEL OF EVIDENCE: V.

Total knee arthroplasty after distal femoral osteotomy: a systematic review and current concepts.

INTRODUCTION: Distal Femoral Osteotomy (DFO) is a common procedure for correcting lower limb valgus deformity and lateral compartment overload. Low 20-year survivorship rate was reported with a consequent need for total knee arthroplasty (TKA). This study aims to review literature and to analyse the influence of a previous distal femoral osteotomy on outcomes of patients undergoing TKA. METHODS: A systematic literature review was performed in PubMed/Medline and Embase in May 2020. Papers were selected based on the following criteria: patient with a previous distal femoral osteotomy; total knee replacement; Pre- and Postoperative outcomes; surgical outcomes: clinical scores, range of motion, radiographic evaluation and revisions for any cause; case series, retrospective studies, observational studies, open-label studies, randomized clinical trials; systematic reviews and meta-analyses were included to extract primitive studies. RESULTS: 306 articles were found, of which five papers were considered eligible for this review. In every study included, postoperative clinical outcomes (Knee Society Score or Hospital for Special Surgery score) statistically improved from the preoperative. Complications were not uncommon; implant survivorship at the available follow-up seems to be similar to primary TKA, although being too short to draw any conclusions. CONCLUSIONS: Limited and highly heterogeneous evidence is currently available on the influence of DFO on outcomes after TKA. Knee replacement improves clinical middle-term outcomes in patients with previous distal femoral osteotomy. In this complex surgery, the use of technical tips and tricks could help surgeons to obtain an accurate knee balancing and better long-term results.

Proximal medial patellar restraints and their surgical reconstruction.

Reconstruction of the medial patellofemoral ligament (MPFL) has been increasing as a surgical solution for treatment of recurrent lateral patellofemoral dislocation. Recent attention has been given to fibers extending from the femur to the quadriceps tendon, proximal to the MPFL, termed the medial quadriceps tendon-femoral ligament. This article briefly reviews the proximal medial patellar restraints and surgical procedures for their reconstruction.

Should the patella be everted during primary total knee arthroplasty? A systematic review of overlapping meta-analyses.

Patellar eversion during total knee arthroplasty (TKA) is a debated issue. The aim of this study is to perform a review of overlapping meta-analyses analyzing clinical outcomes of patellar eversion compared to noneversion. A search was performed in PubMed\MEDLINE, Scopus, and Cochrane Library. Inclusion criteria were meta-analysis of randomized controlled trials (RCTs) or quasi-RCTs;l comparison between TKAs with or without patellar eversion; and at least one outcome, such as reoperation rate, pain, and functional scores. Meta-analyses were evaluated with the A Measurement Tool to Assess Systematic Review (AMSTAR) score, addressing the most relevant one with the Jadad algorithm. Three meta-analyses were identified and included in this review. No significant differences were found regarding complications, quadriceps strength, functional, and radiological outcomes. The meta-analysis by Zan et al. was selected as the best available one. Patellar eversion group showed a shorter tourniquet time but a longer skin incision. In conclusion, eversion and noneversion techniques did not demonstrate any significant or clinically relevant difference. Level of Evidence: Level II, systematic review of meta-analyses.

Italian consensus statement for the use of allografts in ACL reconstructive surgery.

PURPOSE: Graft choice for primary anterior cruciate ligament reconstruction (ACL-R) is debated, with considerable controversy and variability among surgeons. Autograft tendons are actually the most used grafts for primary surgery; however, allografts have been used in greater frequency for both primary and revision ACL surgery over the past decade. Given the great debate on the use of allografts in ACL-R, the "Allografts for Anterior Cruciate Ligament Reconstruction" consensus statement was developed among orthopedic surgeons and members of SIGASCOT (Società Italiana del Ginocchio, Artroscopia, Sport, Cartilagine, Tecnologie Ortopediche), with extensive experience in ACL-R, to investigate their habits in the use of allograft in different clinical situations. The results of this consensus statement will serve as benchmark information for future research and will help surgeons to facilitate the clinical decision making. METHODS: In March 2017, a formal consensus process was developed using a modified Delphi technique method, involving a steering group (9 participants), a rating group (28 participants) and a peer-review group (31 participants). Nine statements were generated and then debated during a SIGASCOT consensus meeting. A manuscript has been then developed to report methodology and results of the consensus process and finally approved by all steering group members. RESULTS: A different level of consensus has been reached among the topics selected. Strong agreement has been reported in considering harvesting, treatment and conservation methods relevant for clinical results, and in considering biological integration longer in allograft compared to autograft. Relative agreement has been reported in using allograft as the first-line graft for revision ACL-R, in considering biological integration a crucial aspect for rehabilitation protocol set-up, and in recommending a delayed return to sport when using allograft. Relative disagreement has been reported in using allograft as the first-line graft for primary ACL-R in patients over 50, and in not considering clinical results of allograft superior to autograft. Strong disagreement has been reported in using allograft as the first-line graft for primary ACL-R and for skeletally immature patients. CONCLUSIONS: Results of this consensus do not represent a guideline for surgeons, but could be used as starting point for an international discussion on use of allografts in ACL-R. LEVEL OF EVIDENCE: IV, consensus of experts.

Patient-Specific Instrumentation Affects Perioperative Blood Loss in Total Knee Arthroplasty.

Patient-specific instrumentation (PSI) may contribute to reduced blood loss related to total knee arthroplasty (TKA). The purpose of this study was to compare the estimated hemoglobin (Hb) and red blood cell volume (RBC) losses in two groups of patients undergoing TKA with PSI and conventional instrumentation. Pre- and postoperative blood samples were collected from 22 patients randomly assigned to receive a PSI-assisted or conventional TKA. Post- to preoperative Hb difference was calculated and RBC loss was estimated according to Sehat et al. A significant difference in Hb reduction in favor of the PSI group was registered on the last day of stay (p = 0.0084) and significant treatment effect (p = 0.027) on Hb reduction after intervention was found with a regression model for longitudinal measurements. This study demonstrated that PSI leads to a significant trend in earlier Hb regain. These promising results suggest a beneficial effect of PSI in blood loss reduction.

Treatment of unstable knee osteochondritis dissecans in the young adult: results and limitations of surgical strategies-The advantages of allografts to address an osteochondral challenge.

Joint surface incongruence resulting from osteochondritis dissecans (OCD) alters the articular physiologic congruence, increasing the contact stress on adjacent joint surfaces and accelerating wear and the cascade of joint degeneration. Accordingly, the restoration of articular surface integrity is of major importance, especially in young adults where, in lesions left untreated or following simple fragment excision, early osteoarthritis can be anticipated. Therefore, the treatment algorithm in unstable knee OCD of the young adult foresees surgical options to restore the articular surface. Several procedures have been proposed, including refixation of the detached fragment bone marrow stimulation, osteochondral autograft implantation, fresh osteochondral allograft transplantation, and cell-based or cell-free regenerative techniques. The aim of this review was to summarize the evidence for these surgical strategies, reporting their results and limitations. The overall evidence documents positive results for each of the assorted surgical procedures applied to treat unstable OCD, thus indicating support for their selected use to treat osteochondral defects paying particular attention to their specific indications for the lesion characteristics. The fixation of a good quality fragment should be pursued as a first option, while unfixable small lesions may benefit from autografts. For large lesions, available cell-based or cell-free osteochondral scaffold are a feasible solution but with limitation in terms of regenerated tissue quality. In this light, fresh allografts may offer articular surface restoration with viable physiologic osteochondral tissue providing a predictably successful outcome, and therefore they may currently represent the most suitable option to treat unstable irreparable OCD lesion in young adults. LEVEL OF EVIDENCE: V.

Use of an Elastomeric Knee Brace in Patellofemoral Pain Syndrome: Short-Term Results.

Purpose This article verifies the effectiveness of a new brace on patellofemoral pain syndrome (PFPS) in adjunct to a specifically developed rehabilitation program. Methods Two groups of 30 patients with PFPS were prospectively and randomly allocated to a rehabilitation protocol, with (group A) or without (group B) the use of a specific brace. All the patients were assessed at 3, 6, and 12 months using the disease-specific Kujala scale and a visual analog scale (VAS) for pain; time to return to sport and patient satisfaction with the brace were also recorded. Results Kujala scale's values showed constant and progressive improvement. The mean score at 6 months was 79.8 ± 6.8 points in group A and 76.8 ± 8.6 in group B, rising at 12 months to 80.9 ± 7.5 in group A and 78.4 ± 8.3 in group B. VAS scores significantly differed ( p < 0.05) between the two groups at both 6 and 12 months; the score recorded at 12 months was 0.9 ± 1.3 in the brace-treated group and 1.8 ± 1.6 in the controls. The patients who used a brace showed a quicker return to sports and 75% of the patients in this group were satisfied. Conclusion All the scores improved progressively in both groups. The most significant improvement concerned pain, showing that the brace used in this study may allow a better subjective outcome and a quicker return to sport. Level of Evidence Level II, prospective randomized controlled trial.

Italian consensus conference on guidelines for conservative treatment on lower limb muscle injuries in athlete.

Provide the state of the art concerning (1) biology and aetiology, (2) classification, (3) clinical assessment and (4) conservative treatment of lower limb muscle injuries (MI) in athletes. Seventy international experts with different medical backgrounds participated in the consensus conference. They discussed and approved a consensus composed of four sections which are presented in these documents. This paper represents a synthesis of the consensus conference, the following four sections are discussed: (i) The biology and aetiology of MIs. A definition of MI was formulated and some key points concerning physiology and pathogenesis of MIs were discussed. (ii) The MI classification. A classification of MIs was proposed. (iii) The MI clinical assessment, in which were discussed anamnesis, inspection and clinical examination and are provided the relative guidelines. (iv) The MI conservative treatment, in which are provided the guidelines for conservative treatment based on the severity of the lesion. Furthermore, instrumental therapy and pharmacological treatment were discussed. Knowledge of the aetiology and biology of MIs is an essential prerequisite in order to plan and conduct a rehabilitation plan. Another important aspect is the use of a rational MI classification on prognostic values. We propose a classification based on radiological investigations performed by ultrasonography and MRI strongly linked to prognostic factors. Furthermore, the consensus conference results will able to provide fundamental guidelines for diagnostic and rehabilitation practice, also considering instrumental therapy and pharmacological treatment of MI. Expert opinion, level IV.

Surgical Treatment of Objective Patellar Instability: Long-Term Results.

Purpose To evaluate the long-term results of classical "à la carte" surgical treatment of objective patellar instability as proposed by Dejour in 1987. Methods A multicentric retrospective study was conducted evaluating patients that underwent surgical procedure with a 10-year minimum follow-up (mean 12.7; range, 10-15). Surgical procedures were medial transfer of the tibial tubercle transfer according to Elmslie and Trillat et al in 38 cases, plasty of the vastus medialis obliquus according to Insall in 15 cases, open lateral retinacular release in 13 cases, capsuloplasty in 3 cases, and trochleoplasty in 1 case. Different combinations of surgical procedures were adopted according to the pathological features. Subjective outcome was assessed with the visual analog scale (VAS), Kujala score, subjective International Knee Documentation Committee (IKDC) score, Tegner score, and Crosby and Insall scale. Radiographic exams were used to assess the patellar tilt by the Laurin's angle and patellofemoral osteoarthritis (OA) according to the Iwano radiological OA scale. Results Forty patients were evaluated. Subjectively, 60% of patients achieved a result judged good, 34% sufficient, and 6% poor. There were only two cases of recurrence of instability. Mean score results were Kujala score 73.4 ± 9.9 (range, 55-95), VAS 4.5 ± 1.2 (range, 1-6), IKDC 64.8 ± 7.9 (range, 51-88), and Tegner score 4. Only nine patients returned to sports activities). Ten patients developed a grade I patellofemoral OA, 8 patients a grade II, and 22 patients a grade III. Average patellar tilt was 10° ± 3.9°. Conclusion This retrospective study showed that the traditional surgical procedure was successful for the treatment of patellar instability, but it did not prevent symptomatic patellofemoral OA. Level of Evidence Level IV, retrospective case series.

Significant differences between manufacturer and surgeon in the accuracy of final component size prediction with CT-based patient-specific instrumentation for total knee arthroplasty.

PURPOSE: Patient-specific instrumentation (PSI) for total knee arthroplasty (TKA) may improve component sizing. Little has been reported about accuracy of the default plan created by the manufacturer, especially for CT-based PSI. The goal of this study was to evaluate the reliability of this plan and the impact of the surgeon's changes on the final accuracy of the guide sizes. METHODS: Forty-five patients eligible for primary TKA were prospectively enrolled. The planned implant sizes were prospectively recorded from the initial manufacturer's proposal and from the final plan adjusted in light of the surgeon's evaluation; these two sizes where then compared to the actually implanted sizes. Fisher's exact test was used to test differences for categorical variables. Agreement between pre-operative plans and final implant was evaluated with the Bland-Altman method. RESULTS: The manufacturer's proposal differed from the final implant in 9 (20.0%) femoral and 23 (51.1%) tibial components, while the surgeon's plan in 6 (13.3%, femoral) and 12 (26.7%, tibial). Modifications in the pre-operative plan were carried out for five (11.1%) femoral and 23 (51.1%) tibial components (p = 0.03). Appropriate modification occurred in 22 (88.0%) and 19 (76.0%) cases of femoral and tibial changes. The agreement between the manufacturer's and the surgeon's pre-operative plans was poor, especially with regard to tibial components. CONCLUSION: The surgeon's accuracy in predicting the final component size was significantly different from that of the manufacturer and changes in the initial manufacturer's plan were necessary to get an accurate pre-operative plan of the implant sizes. CLINICAL RELEVANCE: Careful evaluation of the initial manufacturer's plan by an experienced knee surgeon is mandatory when planning TKA with CT-based PSI. LEVEL OF EVIDENCE: II.