The iliac stemmed cup in reconstruction of the acetabular defects secondary to tumor resection: a systematic review of literature.

INTRODUCTION: Stemmed acetabular cups are suitable for reconstruction in case of important bone loss. Nevertheless, their use is not so common, because generally judged very invasive and technically difficult to implant. The aim of the present review is to verify the results of their use and to evaluate indications and complications. MATERIALS AND METHODS: Literature research was performed in the main healthcare databases; indications, surgical technique, related complications, functional results and implant survival were valued and analyzed for every selected paper. RESULTS: 13 studies were selected, for a population of 424 patients and 428 hips. The main indication was reconstruction after tumor removal; the primary non-oncologic indication was revision for aseptic loosening. The most frequent complications were aseptic loosening and implant failure (16.2%), followed by deep infection (11.3%) and dislocation (9.8%). The average MSTS score was 65.9%; while data regarding functional results for degenerative cases are quite fragmented. The 5-years implant survival was 73.6%. CONCLUSIONS: Data regarding SAC prostheses are quite rare in the literature; no prospective studies with comparisons with other reconstruction techniques are available so their use is mainly based on the experience of single centers. While data for tumors are more consistent and supported by studies, information on revisions of hip prosthesis implanted for degenerative problems is quite scarce. Preliminary results on the SAC prosthesis as a valid alternative both for tumoral and degenerative revision cases are encouraging. Prospective randomized studies are advocated to value results compared to alternative techniques.

Primary complex total knee arthroplasty with severe varus deformity and large bone defects: mid-term results of a consecutive series treated with primary implants.

INTRODUCTION: In recent years, the use of constrained implants in complex primary TKA has gained popularity since these implants may better and more easily address severe instability present in complex primary cases (CPC). However, the need for a constrained TKA in CPC is controversial. We hypothesized that a standard TKA may be successful in most of CPC and that an intraoperative switching to a constrained device is rarely need even in the presence of severe instability and bone loss. MATERIALS AND METHODS: A consecutive series of 24 CPC (28 knees) were analysed retrospectively. Inclusion criteria were a femoro-tibial angle > 12° and bone defect of grade 2-3 (group 1). Forty-eight patients (52 knees) were analysed as controls (group 2). Patients were followed up clinically and radiographically up to a minimum of 5 years. RESULTS: In group 1, a PS was used in 24 knees and a CR in 4. In no patient, a CCK or RHK was implanted. Bone defect was treated with bone cement plus cortical screws in 15 knees (53.5%), a medial wedge in 8 (28.5%), a medial wedge plus bone grafting with cancellous screws in 5 (17.8%). Metaphyseal sleeve or cone was not used. At the last follow-up, no significant difference was found in the clinical scores between the 2 groups. CONCLUSION: In CPC with marked varus deformity, instability and bone loss, the use of primary TKA is associated with a clinical outcome comparable to standard cases. Ligamentous balancing may be addressed using primary implants and simple cost-effective techniques may be used to manage an extensive bone loss. In most CPC, an intraoperative switching to a constrained device is not necessary.

Correlations Between Radial Head Diameters and Humeral Articular Dimensions: Bilateral MRI Morphometric Analysis on 39 Healthy Subjects.

PURPOSE: Choosing the correct size of head component in radial head arthroplasty is often challenging, particularly in comminuted fractures, deformities, and revision surgery. The main aim of this study was to investigate possible correlations between radial head diameters and the morphometric parameters of the articular distal humerus in order to find mathematical equations that may be used to infer radial head dimensions indirectly. METHODS: We performed bilateral elbow magnetic resonance imaging on 39 healthy young subjects, comprising 19 women and 20 men, with a mean age of 28 years (range, 21-32 years). The following measurements, which included cartilage thickness, were calculated on the axial plane: maximum (Dmax) and minimum (Dmin) radial head diameters, capitellum width, capitellum to lateral trochlear ridge width (CAP-TROCHridge), humeral articular width (HUMwidth), capitellum radius of curvature, and lateral, medial, and total trochlear width. The anteroposterior diameters of the capitellum, trochlear sulci, and lateral and medial trochlear ridges were measured on the sagittal plane. RESULTS: CAP-TROCHridge and HUMwidth were found to be the parameters most strongly correlated with the radial head diameters. Four mathematical equations that allowed Dmax and Dmin to be calculated with an average residual error less than 1 mm, were obtained. The intraclass coefficient was greater than 0.95 for all the measurements. CONCLUSIONS: Radial head diameters can be accurately inferred from 2 humeral dimensions by magnetic resonance imaging. The HUMwidth, which is not influenced by cartilage thickness, may be useful for planning with preoperative imaging because it can also be calculated by computed tomography scan, whereas CAP-TROCHridge, which is influenced by cartilage thickness, might be useful for direct intraoperative measurement. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic III.

Chronic complex persistent elbow instability: a consecutive and prospective case series and review of recent literature.

BACKGROUND: Chronic complex persistent elbow instability (CCPEI) is a condition that even expert elbow surgeons find challenging to treat. The results of the few studies that have dealt with the treatment of this condition are conflicting. We describe the surgical results of a consecutive prospective series of patients with CCPEI and provide a review of the recent literature. METHODS: We assessed 21 patients with previous failed surgical or conservative treatment, with a terrible-triad injury in 13, Monteggia-like lesion in 6, humeral shear fracture-dislocation in 1, and radial head fracture-dislocation in 1. Overall, 21 open débridement procedures, 15 ulnar nerve transpositions, 6 ulnar in situ neurolysis procedures, 7 total elbow arthroplasties, 8 radial head arthroplasties, 1 radial head resection with humeroradial anconeus interpositional arthroplasty, 4 coronoid graft reconstructions, 14 ligament retensioning procedures, 3 ulnar nonunion treatments, and 2 ulnar osteotomies were performed. Two dynamic external fixators were applied. The Mayo Elbow Performance Score, quick Disabilities of the Arm, Shoulder and Hand score, and modified American Shoulder and Elbow Surgeons score were used preoperatively and postoperatively. RESULTS: The mean follow-up period was 29.4 months. A significant improvement was found between preoperative and postoperative clinical scores and range-of-motion values. The reintervention and major complication rates were 19% and 23%, respectively. Arthritic evolution was observed in 71% of the cases. CONCLUSIONS: CCPEI is a challenging condition with an uncertain prognosis. The variability in patients' pathoanatomic conditions requires customized surgical treatment aimed at elbow stabilizer reconstruction when the ulnohumeral joint is preserved or aimed at joint replacement in case of severe articular degeneration. The time interval between the initial trauma and index surgical procedure significantly affects the feasibility of reconstructive procedures.

Post-traumatic proximal radioulnar synostosis: results of surgical treatment and review of the literature.

BACKGROUND: Post-traumatic proximal radioulnar synostosis is a very rare and disabling condition whose surgical treatment has traditionally been viewed with pessimism. The results of the few case series in the literature are conflicting. Our aims were (1) to describe the clinical results of a case series treated surgically by a single elbow surgeon and (2) to review the literature. METHODS: Twelve patients were evaluated. Preoperative radiographs and computed tomography scans were performed. According to the Viola and Hastings classification, there was 1 case of type IC synostosis; 3, type IIA; 2, type IIIA; and 8, type IIIB. Two patients had a double synostosis. The synostosis was excised in 10 cases; in addition, radial head excision, radial head arthroplasty, and proximal radial diaphyseal resection were performed in 1, 3, and 2 cases, respectively. The Mayo Elbow Performance Score, modified American Shoulder and Elbow Surgeons score, and QuickDASH (short version of Disabilities of the Arm, Shoulder and Hand questionnaire) score were used for the preoperative and postoperative evaluation. The nonparametric Wilcoxon signed rank test was used for the statistical analysis. RESULTS: The mean follow-up period was 20.5 months. The final mean extension-flexion and pronation-supination arcs were 116° and 123°, respectively. Significant improvements were found in the Mayo Elbow Performance Score (P = .005), modified American Shoulder and Elbow Surgeons score (P = .012), and QuickDASH score (P = .002), with mean values of 24, 28, and 17, respectively. One synostosis recurrence and one late disassembly of the radial head arthroplasty were observed. CONCLUSIONS: Post-traumatic proximal radioulnar synostosis surgery is effective, but careful preoperative planning based on the pathoanatomic characteristics of each type of synostosis and associated lesions is mandatory. Synostosis excision is performed in most cases, whereas additional surgical procedures should be considered in selected cases.

The native coronal orientation of tibial plateaus may limit the indications to perform a kinematic aligned total knee arthroplasty.

PURPOSE: To investigate the coronal alignment of tibial plateaus in normal and osteoarthritic knees and to simulate the effects of a tibial cut performed in total knee arthroplasty (TKA) using a kinematic alignment technique with standard instrumentation. METHODS: The coronal alignment of tibial plateaus was measured in three groups including group 1 (reference group), 50 cadaveric tibiae showing no evidence of degenerative changes of tibial plateaus; group 2, 49 patients who underwent MR of the knee, showing no or mild degenerative changes of the knee joint and, group 3, 54 patients with knee osteoarthritis who underwent computer-assisted total knee arthroplasty. RESULTS: The coronal alignment of tibial plateaus averaged 2.4° with no significant differences between groups. The mean coronal orientation of tibial plateaus was 3° ± 2° in men and 1.6° ± 2° in women (p = 0.03). A coronal alignment of tibial plateaus of 3° or more was found in 69 cases (45%) and 5° or more in 23 (14.7%). The simulation of a tibial cut performed with an error of 3° in varus in 15% of the subjects showing a native coronal orientation of tibial plateaus of 3° or more, led to a final tibial cut greater 6° in 13.7% of cases. CONCLUSIONS: A coronal alignment of tibial plateaus of 3° or more in varus was found in near half of normal subjects and osteoarthritic patients. A preoperative measurement of the coronal alignment of tibial plateaus is advisable in any patients scheduled for kinematic aligned TKA. As errors in the alignment of the tibial component of 3° or more may occur using standard instrumentations, the results of this study raise questions on performing a kinematic aligned TKA with standard instrumentations. LEVEL OF EVIDENCE: IV.

Complex humeral head fractures treated with blocked threaded wires: maintenance of the reduction and clinical results with two different fixation constructs.

BACKGROUND: Locking plates are the gold standard for treatment of 3-part humeral head fractures, although major complications range from 9% to 36%. Percutaneous techniques may allow vascular supply preservation, maintenance of fracture hematoma, scarce blood loss. Many configurations with Kirschner wires can be performed, generating confusion on result interpretation. We studied the correlation between system configuration, stability, and clinical results in patients with 3-part humeral head fractures treated with the same fixation system but with 2 different biomechanical constructs. MATERIALS AND METHODS: There were 52 consecutive patients (19 men, 33 women; mean age, 63.1 [standard deviation, 5.6] years; range, 48-82 years) with Hertel 7 humeral head fractures. Two fixation constructs composed of 3 couples (construct A) or 4 couples (construct B) of blocked threaded wires were used in 17 and 35 patients, respectively. At the final follow-up, the individual relative Constant Score (irCS) and visual analog scale were measured. Radiographic evaluation according to the Bahr criteria was performed. Statistical analysis was performed. RESULTS: The mean follow-up was 22 months. The mean irCS at the final follow-up was 89.7%. The mean irCS in patients treated with construct A and construct B was 86% and 93%, respectively (P = .043). One nonunion and 2 superficial infections occurred (6%). The postoperative reduction was excellent in 97% of patients and remained excellent in 89%. The mean postoperative neck shaft angle was 135.0° (construct A: 134.7°; construct B: 135.1°), and the final neck shaft angle was 132.9° (construct A: 131.3°; construct B: 133.8°; P = .047). CONCLUSIONS: The functional and radiologic outcomes obtained with percutaneous fixation or locking plates are similar; however, the percentage of major complications after percutaneous treatment is lower. Results of percutaneous fixation depend on the biomechanical construct.

Aetiopathogenesis of cuff-tear arthropathy: Could juvenile joint laxity be considered a predisposing factor?

PURPOSE: Although many hypotheses have been formulated, aetiopathogenesis of cuff-tear arthropathy (CTA) is still motive for discussion. Since prevalence of CTA is notoriously higher in women, as is joint hypermobility, we hypothesised a possible correlation between the two conditions. METHODS: One hundred thirty-three (n = 133) consecutive patients with glenohumeral osteoarthritis [48 men, 85 women; mean age (SD) 72.32 (7.05)] were divided into two groups: Groups 1 (CTA) and 2 (concentric shoulder arthropathy) comprised 71 (22 men, 49 women) and 62 (26 men, 36 women), respectively. The presence of current or previous joint hypermobility was assessed using two standardised methodologies: the Beighton criteria score, and a five-item self-report questionnaire. Data were submitted to statistical analysis. RESULTS: A moderate association between Beighton criteria and the five-item self-report (φ = 0.481, p < 0.001) was detected. Beighton criteria led to a diagnosis of joint hypermobility in 16 patients (22.5%) in Group 1 and 15 (24.2%) in Group 2. According to five-item self-report questionnaire, juvenile joint laxity was diagnosed in 11 (15.5%) and 12 (19.4%) patients in Groups 1 and 2, respectively. No significant association between groups and the Beighton criteria [χ2(1) = 0.051, p = 0.82] and five-item self-report questionnaire [χ2(1) = 0.67, p = 0.41] was found. CONCLUSION: Juvenile joint hyperlaxity is not a predisposing factor for cuff arthropathy. Further studies will be needed to explain CTA aetiopathogenesis. LEVELS OF EVIDENCE: III.

Cartilage thickness of distal humerus and its relationships with bone dimensions: magnetic resonance imaging bilateral study in healthy elbows.

BACKGROUND: Little is known about the cartilage thickness of the distal humerus and how it affects the shape of the articular surface. Our aims were to assess cartilage thickness and to determine the extent to which it affects the true profile of the distal humerus. METHODS: We assessed 78 healthy elbows (39 subjects, 19 women and 20 men) with a mean age of 28 years (range, 21-32 years). Cartilage thickness was measured by use of high-definition magnetic resonance imaging scans at 19 different points of the articular surface, 13 on the trochlea and 6 on the capitellum, on the axial and coronal views. Bone diameters at the medial and lateral trochlear ridges, trochlear groove, and capitellum, as well as the articular surface width, were measured. Subject height was used as an indirect measurement of humerus length. Pearson correlation coefficients and the Student t test were used. RESULTS: Cartilage thickness showed a significant variation (range, 0.4-1.8 mm) independent of sex and side. It appeared thinner at the medial and lateral edges, whereas it increased at the level of the trochleocapitellar and trochlear grooves, the lateral trochlear ridges, and the center of the capitellum. The mean bone diameters of the medial ridge, lateral ridge, trochlear groove, and capitellum measured 25.1 mm, 21 mm, 16.9 mm, and 19.6 mm, respectively. The mean width of the articular surface was 42.9 mm (range, 35.8-50.2 mm). No significant correlation was found between cartilage thickness and bone dimensions. CONCLUSION: Cartilage thickness is not uniform and modifies the morphologic shape and diameters of the humeral articular surface. These findings may be relevant to anatomic prosthesis design.

Contribution of cartilage to size and shape of radial head circumference: magnetic resonance imaging analysis of 78 elbows.

BACKGROUND: The aims of our study were to quantify cartilage thickness at the minimum and maximum diameters of the radial head circumference and to investigate its influence on the size and shape of the proximal radius. METHODS: We analyzed high-definition magnetic resonance imaging scans of 78 healthy elbows in 19 men and 20 women, with a mean age of 28 (21-32) years. All measurements were estimated in the axial plane just distal to the fovea radialis. Maximum and minimum bone diameters, maximum and minimum total diameters (including cartilage thickness), and cartilage thickness were calculated. Cartilage thickness was measured at 4 different points: (1) at the articular side of the maximum diameter (point A), (2) at the nonarticular side of the maximum diameter (point B), (3) at the medial side of the minimum diameter (point C), and (4) at the lateral side of the minimum diameter (point D). Pearson correlation and t test were used for the statistical analysis. RESULTS: Mean maximum and minimum bone diameters and maximum and minimum total diameters were 22.2, 21.5, 24.0, and 23.2 mm, respectively. All differences between diameters were statistically significant. Mean cartilage thickness at points A, C, and D was 1.7, 0.8, and 0.8 mm, respectively. No measurable cartilage thickness was found at point B. No significant correlation was found between bone diameters and cartilage thickness. CONCLUSIONS: Cartilage surface significantly increases and modifies the size and shape of the radial head. The observation that cartilage thickness varies between subjects and does not correlate with bone parameters suggests that the diameters of the radial head cannot be inferred from indirect measurements of dry bones or radiographs.

Erratum.

Results - Total alcohol consumption, wine consumption, and duration of alcohol intake were higher in both men and women with RCT than in both men and women in the control group. Excessive alcohol consumption was found to be a risk factor for the occurrence of RCT in both sexes (men: OR =3.0, CI: 1.5-6.0, p < 0.001; women: OR =3.6, CI: 1.7-7.8, p < 0.001). Massive tears were associated with a higher intake of alcohol (especially wine) than smaller lesions.

Association between alcohol consumption and rotator cuff tear.

BACKGROUND AND PURPOSE: Long-term alcohol intake is associated with various negative effects on capillary microcirculation and tissue perfusion. We hypothesized that alcohol consumption might be a risk factor for both the occurrence and the severity of rotator cuff tears (RCTs). PATIENTS AND METHODS: A case-control study was performed. We studied 249 consecutive patients (139 men and 110 women; mean age 64 (54-78) years) who underwent arthroscopic rotator cuff repair. Tear size was determined intraoperatively. The control group had 356 subjects (186 men and 170 women; mean age 66 (58-82) years) with no RCT. All participants were questioned about their alcohol intake. Participants were divided into: (1) non-drinkers if they consumed less than 0.01 g of ethanol per day, and (2) moderate drinkers and (3) excessive drinkers if women (men) consumed > 24 g (36 g) per day for at least 2 years. RESULTS: Total alcohol consumption, wine consumption, and duration of alcohol intake were higher in both men and women with RCT than in both men and women in the control group. Excessive alcohol consumption was found to be a risk factor for the occurrence of RCT in both sexes (men: OR = 1.7, 95% CI: 1.2-3.9; women: OR = 1.9, 95% CI: 0.94-4.1). Massive tears were associated with a higher intake of alcohol (especially wine) than smaller lesions. INTERPRETATION: Long-term alcohol intake is a significant risk factor for the occurrence and severity of rotator cuff tear in both sexes.

The ulnar greater sigmoid notch "coverage angle": bone and cartilage contribution. Magnetic resonance imaging anatomic study on 78 elbows.

BACKGROUND: To study the degree of coverage provided by the greater sigmoid notch (GSN) to the humeral trochlea, as well as the contribution of the olecranon and coronoid process cartilage tips to this angle, and its variations. METHODS: We recruited 39 healthy volunteers, comprising 19 women and 20 men, with a mean age of 28 years (range, 21-32 years). High-definition magnetic resonance images were obtained for the right and left elbows. Four angles were measured on the sagittal plane passing through the coronoid and olecranon tips: angle A, identified by 2 lines from the trochlea center to the olecranon bone-cartilage junction and olecranon cartilage tip; angle B, identified by 2 lines from the trochlea center to the olecranon and coronoid bone-cartilage junction; angle C, identified by 2 lines from the trochlea center to the coronoid bone-cartilage junction and coronoid cartilage tip; and GSN coverage angle (GSN-ca), defined as the sum of angles A, B, and C. Pearson correlation tests, t tests, and intraclass correlation coefficients were used for statistical analyses. RESULTS: The mean angle A, angle B, and angle C values were 6° (range, 2°-12°), 182° (range, 153°-204°), and 9° (range, 2°-16°), respectively. No correlations were found between these 3 angles. The mean GSN-ca was 198° (range, 167°-222°), and the GSN-ca was less than 180° in 8% of the cases. No significant differences emerged for side or gender or for total length of the ulna. CONCLUSION: The GSN showed significantly different shapes on the sagittal plane that we defined as closed type when the GSN-ca was greater than 180° (92%) and as open type when the GSA-ca was less than 180° (8%). The cartilage tip contribution varied and was not correlated with that of bone.

Discovery elbow system: 2- to 5-year results in distal humerus fractures and posttraumatic conditions: a prospective study on 24 patients.

PURPOSE: To prospectively evaluate preliminary results of the Discovery Elbow System (DES) used for acute distal humerus fractures and posttraumatic conditions. METHODS: We analyzed 24 patients (9 men and 15 women), with a mean age of 69 years (range, 45-89 y). Ten had comminuted distal humerus fractures (group I), and 14 had severe post-traumatic arthritis, chronic instability, or nonunion (group II). Clinical and radiographic evaluations were performed. The preoperative (group II) and postoperative (both groups) evaluations were assessed with the Mayo Elbow Performance Score and Mayo Elbow Performance Index, the Quick Disabilities of the Arm, Shoulder, and Hand score, and the modified American Shoulder and Elbow Surgeons score. Patient satisfaction was evaluated on a 4-point scale. RESULTS: Mean follow-up was 41 months (range, 29-63 mo). At the last evaluation, average flexion, extension, pronation, and supination were 136°, 17°, 80°, and 83°, respectively. The average Mayo Elbow Performance Score, Quick Disabilities of the Arm, Shoulder, and Hand score, and the modified American Shoulder and Elbow Surgeons score were 96, 20, and 84, respectively, and without significant intergroup differences. According to the Mayo Elbow Performance Index, there were 20 excellent, 3 good, and 1 fair result. Twenty patients were very satisfied or satisfied with the outcome. A significant increase in the functional scores was observed in group II compared with preoperative results. Radiological evaluation showed 1 patient with progressive radiolucency and 1 with a nonprogressive radiolucency at the final follow-up. No mechanical failures were observed. Two transient ulnar neuropathies, 1 wound infection, and 1 epicondyle fracture were observed. CONCLUSIONS: The DES yielded promising 2- to 5-year results in the treatment of acute fractures and posttraumatic conditions regarding pain relief, functional improvement, and patient satisfaction, achieving excellent results in most cases. The DES may represent an effective linked-implant option for total elbow replacement in such patients. However, long-term studies are needed. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Intensity and distribution of shoulder pain in patients with different sized postero-superior rotator cuff tears.

BACKGROUND: The vast majority of studies regarding rotator cuff tears (RCTs) are focused on etiopathogenesis and treatments, but information on shoulder pain characteristics needs further investigation. We analyzed the intensity and distribution of shoulder pain in patients with different sizes of RCTs. METHODS: Two hundred eighty-five consecutive patients with postero-superior RCTs were enrolled for this study. Tear size was intraoperatively classified. Before surgery, all patients completed an upper limb pain map (dermatome map made by Keegan). Shoulder pain intensity was assessed with a visual analogue scale (VAS). Data were submitted to statistical analysis. RESULTS: Shoulder pain intensity caused by a RCT was greater in females (P = .024); it did not vary with the side nor with age. Pain intensity was less in massive tears (P < .05) and in patients whose pain was distributed only to the shoulder (P = .035). Furthermore, patients whose pain persisted for more than 6 months maintained the same pain intensity. Pain was localized predominantly on dermatomes C5-C6, was more diffuse in massive tears (P < .05), and rarely extended beyond the elbow. In the presence of intense shoulder pain, its precise distribution was not well-delimited. CONCLUSION: Shoulder pain characteristics in patients with RCTs may be influenced by gender and size of tear. Cuff tear pain distribution principally involves the antero-lateral aspect of the shoulder with extension down the lateral surface of the arm to the elbow. Information about pain intensity and distribution in patients with RCTs may contribute to a more accurate diagnosis. LEVELS OF EVIDENCE: Level III, cross sectional study.

Higher rates of fully preserved posterior cruciate ligament in total knee arthroplasty using a double tibial cut: a prospective randomized controlled trial.

PURPOSE: In cruciate retaining total knee arthroplasty, posterior cruciate ligament damage may occur during tibial cutting. A prospective randomized study was conducted to investigate whether a novel tibial cutting technique was more effective than the currently used techniques. MATERIALS AND METHODS: Patients undergoing cruciate retaining total knee arthroplasty were recruited in a prospective, randomized, controlled trial. In 25 patients (group 1) the tibial cut was performed using a double tibial cut technique; in 25 (group 2) and 25 (group 3) patients, the bone island and en bloc resection techniques were performed, respectively. Posterior cruciate ligament integrity and femoral rollback were assessed at the end of surgery. The Oxford Knee Score, WOMAC score and range of motion were assessed postoperatively. RESULTS: Posterior cruciate ligament was completely preserved in 92% of patients in group 1 and in 64% in group 2 and 3, respectively (p = 0.03). The Oxford Knee Score and WOMAC scores did not differ between groups (p = 0.4). The mean knee flexion was 126.4°, 121.5° and 123.9° in groups 1, 2 and 3, respectively (p = 0.04). The femoral rollback at 120° flexion was 80.7%, 72.2% and 75.4% in groups 1, 2 and 3, respectively (p = 0.01). CONCLUSIONS: The double cut technique preserves the posterior cruciate ligament at significantly higher rates than the bone island or en bloc resection techniques. Better posterior cruciate ligament preservation may improve the femoral rollback and knee flexion. LEVEL OF EVIDENCE: Prospective randomized controlled trial, Level I.

Stress Shielding around Press-Fit Radial Head Arthroplasty: Proposal for a New Classification System Based on the Analysis of 97 Patients with a Mid-Term Follow-Up and a Review of the Literature.

Stress shielding (SS) around press-fit radial head arthroplasty (RHA) was recently reported as a cause of a new type of proximal radial neck resorption (PRNR). Very few studies have analyzed this phenomenon. No comprehensive classification is currently available. We thus decided to clinically and radiographically analyze 97 patients who underwent a press-fit RHA and who were followed up for a mean period of 72 months (range: 2-14 years). PRNR in the four quadrants of the radial neck was assessed. We designed a novel SS classification based on (1) the degree of resorption of the length of the radial neck and (2) the number of neck quadrants involved on the axial plane. The mean PRNR (mPRNR) was calculated as the mean resorption in the four quadrants. mPRNR was classified as mild (<3 mm), moderate (3 to 6 mm), and severe (>6 mm). Eighty-four percent of the patients presented PRNR. mPRNR was mild in 33% of the patients, moderate in 54%, and severe in 13%. In total, 6% of the patients with mild mPRNR displayed resorption in one quadrant, 18% displayed resorption in two quadrants, 4% displayed resorption in three quadrants, and 72% displayed resorption in four quadrants. All four quadrants were always involved in moderate or severe mPRNR, with no significant differences being detected between quadrants (p = 0.568). mPRNR has no apparent effect on the clinical results, complications, or RHA survival in the medium term. However, longer-term studies are needed to determine the effects of varying degrees of PRNR on implant failure.

A pathogenic role for brain-derived neurotrophic factor (BDNF) in fibrous dysplasia of bone.

Brain derived neurotrophic factor (BDNF) is a neurotrophin, expressed in the central nervous system and in peripheral tissues, that is regulated by the Gsα/cAMP pathway. In bone, it regulates osteogenesis and stimulates RANKL secretion and osteoclast formation in osteolytic tumors such as Multiple Myeloma. Fibrous dysplasia (FD) of bone is a rare genetic disease of the skeleton caused by gain-of-function mutations of the Gsα gene in which RANKL-dependent enhanced bone resorption is a major cause of bone fragility and clinical morbidity. We observed that BDNF transcripts are expressed in human FD lesions. Specifically, immunolocalization studies performed on biopsies obtained from FD patients revealed the expression of BDNF in osteoblasts and, to a lower extent, in the spindle-shaped cells within the fibrous tissue. Therefore, we hypothesized that BDNF can play a role in the pathogenesis of FD by stimulating RANKL secretion and bone resorption. To test this hypothesis, we used the EF1α-GsαR201C mouse model of the human disease (FD mice). Western blot analysis revealed a higher expression of BDNF in bone segments of FD mice compared to WT mice and the immunolabeling pattern within mouse FD lesions was similar to that observed in human FD. Treatment of FD mice with a monoclonal antibody against BDNF reduced the fibrous tissue along with the number of osteoclasts and osteoblasts within femoral lesions. These results reveal BDNF as a new player in the pathogenesis of FD and a potential molecular mechanism by which osteoclastogenesis may be nourished within FD bone lesions. They also suggest that BDNF inhibition may be a new approach to reduce abnormal bone remodeling in FD.

Clinical usefulness of proximal ulnar and radial fracture-dislocation comprehensive classification system (PURCCS): prospective study of 39 cases.

BACKGROUND: Complex fracture-dislocations of the proximal ulna and radius represent a challenge even for expert orthopaedic surgeons. A new comprehensive classification, the proximal ulnar and radial fracture-dislocation comprehensive classification system (PURCCS), was recently proposed. The aim of this study was to analyze the clinical usefulness of this classification in a large series of patients. MATERIALS AND METHODS: We studied 38 patients (39 elbows) with a mean age of 56 years. All patients were classified with the PURCCS by use of standard radiography, computed tomography, and intraoperative fluoroscopy. Surgical treatment was performed according to the PURCCS therapeutic algorithm. Patients were followed up for a mean of 23 months. The clinical evaluation was performed with the Mayo Elbow Performance Score and Index (MEPS and MEPI); the Disabilities of the Arm, Shoulder, and Hand (DASH) score; and the modified American Shoulder and Elbow Surgeons (m-ASES) score. RESULTS: Each pattern of fracture-dislocation in our series finds its position within the PURCCS. At the last follow-up, the mean MEPS, DASH score, and m-ASES score were 91.2, 14.9, and 83.9, respectively. The mean extension, flexion, pronation, and supination were 19°, 136°, 81°, and 79°, respectively. According to the MEPI, 72%, 20%, and 8% of cases were rated excellent, good, and fair, respectively. Two patients with elbow stiffness underwent a reoperation, with final satisfactory results. CONCLUSION: The PURCCS helps identify the main lesions of each injury pattern; the associated therapeutic algorithm helps select correct surgical strategies. This study showed that the clinical results were satisfactory in the majority of cases, with few major complications and reinterventions. The PURCCS is a comprehensive classification that may contribute to the surgical management of these difficult fracture-dislocations. LEVEL OF EVIDENCE: Level IV, case series, treatment study.

Influence of cartilage and menisci on the sagittal slope of the tibial plateaus.

We analyzed the magnetic resonance studies of the knee in 80 subjects, 45 men and 35 women with a mean age of 38.9 years, who showed no pathological condition of the joint. Using an imaging visualization software, the sagittal longitudinal axis of the tibia was identified. The angle between this axis and a line tangent to the bone profile of the tibial plateau (bone slope) and to the superior border of the menisci (meniscal slope) were calculated. Thickness of anterior and posterior portion of menisci and underlying cartilage were also measured. The bone slope averaged 8° and 7.7° on the medial and lateral sides, respectively. The mean meniscal slope was 4.1° and 3.3° on the medial and lateral sides, respectively, with a significant difference compared with the bone slope. Menisci and underlying cartilage were significantly thicker in their posterior than their anterior portion (7.6 and 5.2 mm, respectively, in the medial compartment; 8.6 and 5.2 mm, respectively, in the lateral compartment). The presence of cartilage and menisci implies a significant decrease in the posterior tibial slope. In the lateral compartment, the greater the bone slope, the larger the difference between bone and meniscal slope, which means that a marked posterior tilt of the lateral tibial plateau is decreased by the cartilage and meniscus. These findings should be taken into account in planning surgical procedures which affect the slope of the articular tibial surface.