Validity and reliability of the Unified Classification System applied to periprosthetic femur fractures: a comparison with the Vancouver system.

Objective: The Unified Classification System (UCS) presents itself as an evolution of the Vancouver Classification (VCS) for the evaluation of periprosthetic fractures of the proximal femur (PPF). The aim of our study was to highlight any loss of reproducibility or validity of the new classification system, compared to the previous one.Material and methods: We tested the interobserver and intraobserver agreement using 40 PPF clinical cases. Each classifying subtype of the UCS and VCS was present in at least two cases. Six experienced hip surgeons (Senior Surgeon, SS) and 5 surgeons in training (Junior Surgeon, JS) classified the clinical cases, using VCS and UCS. The validity of both classifications was then tested with intraoperative surveys.Results: The mean κ value for interobserver agreement for the VCS in the JS group was 0.65 and 0.81 for the SS group. The mean κ value for interobserver agreement for the UCS in the JS group was 0.63 and 0.65 for the SS group. The mean κ value for intraobserver agreement for the VCS in the JS group was 0.71 and 0.73 for the SS group. The mean κ value for intraobserver agreement for the UCS in the JS group was 0.72 and 0.7 for the SS group. Validity analysis showed a moderate agreement for the VCS and a good agreement for the UCS.Conclusion: The UCS completes the Vancouver classification, expanding it. It is reliable, despite the increase in classification categories and number of parameters to evaluate, with a slightly higher validity.

Radiographic evaluation of hip resurfacing: the role of x-rays in the diagnosis of a problematic resurfaced hip.

INTRODUCTION: Hip resurfacing (HRA) requires a new standardised radiographic evaluation protocol. Evaluation of acetabular components is similar to total hip arthroplasty (THA) but femoral components require different criteria. This study evaluates the efficacy of a new femoral zonal system for radiographic HRA assessment in identifying clinical problems. METHODS: A new proximal femoral zonal system divides implant-cement-bone interfaces at head and neck into 7 DeSmet zones. 611 in situ and 100 revised HRA were assessed for component positioning, borderline findings (reactive lines, cortical thickening, cancellous condensation) or sinister findings (lucent lines, bone resorption, osteolysis). Findings were correlated with gender, size, implant survival, clinical scores, metal ions, and adverse soft tissue reactions (ALTR). RESULTS: Radiological changes were found in 265 hips (37.3%), 154 sinister (21.7%) and 111 borderline (15.6%). 84% of revisions had sinister findings versus 11.4% of in situ HRA (p < 0.001). The mean number of abnormal acetabular and femoral zones was 3.3 in revised compared to 0.6 in situ HRA (p < 0.001). Sinister findings were associated with female gender, lower clinical scores, smaller sizes or ASR design (all: p < 0.001). Metal ions were higher with sinister (p < 0.001) and borderline (p < 0.01) findings compared to normal radiographs. Pathological findings in ⩾4 zones had a sensitivity of 50% and specificity of 94.2% (AUC = 0.898) in detecting hips with ALTR (odds ratio = 49). CONCLUSION: In order to accurately evaluate progressive radiographic changes in HRA, specific zones have been established around the femoral component. There was a high correlation between radiographic findings and outcome measures. 84% of problematic hips and 90.4% of proven ALTR had sinister changes.

Hip resurfacing arthroplasty complicated by mismatched implant components.

Metal-on-metal hip resurfacing has gained popularity as a feasible treatment option for young and active patients with hip osteoarthritis and high functional expectations. This procedure should only be performed by surgeons who have trained specifically in this technique. Preoperative planning is essential for hip resurfacing in order to execute a successful operation and preview any technical problems. The authors present a case of a man who underwent a resurfacing arthroplasty for osteoarthritis of the left hip that was complicated by mismatched implant components that were revised three days afterwards for severe pain and leg length discrepancy. Such mistakes, although rare, can be prevented by educating operating room staff in the size and colour code tables provided by the companies on their prostheses or implant boxes.

Italian version of University of California at Los Angeles (UCLA) Activity Score: cross-cultural adaptation.

Over the last 10 years, patient-oriented evaluations using questionnaires have become an important aspect of clinical outcome studies. Any questionnaire must be translated and culturally adapted in order to be used with different language groups, and the translated version must then be evaluated for reliability, validity and responsiveness which are fundamental attributes of any measurement tool. The aim of this study is the validation, translation and cross-cultural adaptation of the Italian version of UCLA activity Score, following the Guillemin criteria. The results show that our Italian version of the UCLA score has the following: reproducibility expressed as ICC=0.994, an internal consistency calculated as Spearman-Brown coefficient=0.754 and finally the construct validity has demonstrated a significant Pearson's correlation coefficient with other validated hip questionnaires.

The 2012 Otto Aufranc Award: The interpretation of metal ion levels in unilateral and bilateral hip resurfacing.

BACKGROUND: The interpretation of metal ion concentrations and their role in clinical management of patients with metal-on-metal implants is still controversial. QUESTIONS/PURPOSES: We questioned whether patients undergoing hip resurfacing with no clinical problems could be differentiated from those with clinical (pain, loss of function) and/or radiographic (component malpositioning, migration, bone loss), problems based on metal ion levels, and if there was a threshold metal level that predicted the need for clinical intervention. Furthermore, we asked if patient and implant factors differed between these functional groups. METHODS: We retrospectively identified 453 unilateral and 139 bilateral patients with ion measurements at minimum followup of 12 months (mean, 4.3 years; range, 1-12.9 years). Patients were designated as well functioning or poorly functioning based on strict criteria. The acceptable upper levels within the well-functioning group were determined from the 75th percentile plus 1.5× interquartile range. The sensitivity and specificity of these levels to predict clinical problems were calculated. RESULTS: Well-functioning group ions were lower than the poorly functioning group ion levels. The acceptable upper levels were: chromium (Cr) 4.6 µg/L, cobalt (Co) 4.0 µg/L unilateral and Cr 7.4 µg/L, Co 5.0 µg/L bilateral. The specificity of these levels in predicting poor function was high (95%) and sensitivity was low (25%). There were more males in the well-functioning group and more females and smaller femoral components in the poorly functioning group. CONCLUSIONS: Metal levels higher than these proposed safe upper limits can predict problems with metal-on-metal resurfacings and are important parameters in the management of at-risk patients. LEVEL OF EVIDENCE: Level II, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Complications following correction of the planovalgus foot in cerebral palsy by arthroereisis.

Pes valgus is a pathological condition which occurs in up to 25% of patients with cerebral palsy. Its correction in early age is essential to prevent progression of the deformity and to optimize the patient's function. In younger patients arthroereisis can be considered as a treatment that fills the void between orthotics and arthrodesis. We treated 15 patients (27 feet) with intra- or extra-sinus tarsi arthroereisis. Concomitant Achilles tendon lengthening was performed in 12 feet. Results were good in 19 feet and poor in 8. Even though arthoereisis presents some complications, it can be considered a useful treatment to delay or avoid a Grice subtalar arthrodesis in flexible pes valgus due to cerebral palsy.

Hip subluxation and dislocation in cerebral palsy: outcome of bone surgery in 21 hips.

The prevalence of hip subluxation and dislocation in cerebral palsy ranges between 3% and 75% in the literature. Clinical signs are rigidity, pain and instability. We assessed functionality, stability and symptoms in 20 patients preoperatively and after follow-up. A varus derotation osteotomy was performed in cases with subluxation or dislocation, while a Chiari osteotomy was performed in the presence of a concomitant acetabular dysplasia. Results were good in 64%, fair in 22% and poor in 14% of patients treated with a varus derotation osteotomy. In patients treated with a Chiari osteotomy, results were good in 43% of cases, fair in 43% and poor in 14%. Subluxated or dislocated hips generally show several anomalies: their severity is directly proportional to the degree of neurological impairment. In the most severe cases, correction of just one of such anomalies might not be sufficient to guarantee good results of the surgery.