Intraoperative imaging in hip arthroplasty: a meta-analysis and systematic review of randomized controlled trials and observational studies.

BACKGROUND: Intraoperative fluoroscopy (IFC) is gaining popularity in total hip arthroplasty (THA), with the aim to achieve better component positioning and therefore eventually reduced revision rates. This meta-analysis investigated the benefit of IFC by comparing it to intraoperative assessment alone. The primary outcome was component positioning and the secondary outcomes included complications and revision rates. METHODS: PubMed, Embase and Cochrane Central Register of Controlled Trials were searched for both randomized clinical trials (RCT) and observational studies. Effect estimates for radiographic cup position, offset/leg length difference and outliers from a safe zone were pooled across studies using random effects models and presented as a weighted odds ratio (OR) with a corresponding 95% confidence interval (95% CI). RESULTS: A total of 10 observational studies involving 1,394 patients were included. No randomized trials were found. IFC showed no significant reduction in acetabular cup position (inclination and anteversion), offset, leg-length discrepancies, revision (none reported) or overall complication rates. CONCLUSION: The current meta-analysis found no differences in cup positioning, offset, leg length discrepancy, the incidence of complications or revision surgery. It should be acknowledged that the included studies were generally performed by experienced surgeons. The benefit of intraoperative fluoroscopy might become more evident at an early phase of the learning curve for this procedure. Therefore, its role has yet to be defined.

Impact of Anterior Malposition and Bone Cement Augmentation on the Fixation Strength of Cephalic Intramedullary Nail Head Elements.

Background and Objectives: Intramedullary nailing of trochanteric fractures can be challenging and sometimes the clinical situation does not allow perfect implant positioning. The aim of this study was (1) to compare in human cadaveric femoral heads the biomechanical competence of two recently launched cephalic implants inserted in either an ideal (centre-centre) or less-ideal anterior off-centre position, and (2) to investigate the effect of bone cement augmentation on their fixation strength in the less-ideal position. Materials and Methods: Fourty-two paired human cadaveric femoral heads were assigned for pairwise implantation using either a TFNA helical blade or a TFNA screw as head element, implanted in either centre-centre or 7 mm anterior off-centre position. Next, seven paired specimens implanted in the off-centre position were augmented with bone cement. As a result, six study groups were created as follows: group 1 with a centre-centre positioned helical blade, paired with group 2 featuring a centre-centre screw, group 3 with an off-centre positioned helical blade, paired with group 4 featuring an off-centre screw, and group 5 with an off-centre positioned augmented helical blade, paired with group 6 featuring an off-centre augmented screw. All specimens were tested until failure under progressively increasing cyclic loading. Results: Stiffness was not significantly different among the study groups (p = 0.388). Varus deformation was significantly higher in group 4 versus group 6 (p = 0.026). Femoral head rotation was significantly higher in group 4 versus group 3 (p = 0.034), significantly lower in group 2 versus group 4 (p = 0.005), and significantly higher in group 4 versus group 6 (p = 0.007). Cycles to clinically relevant failure were 14,919 ± 4763 in group 1, 10,824 ± 5396 in group 2, 10,900 ± 3285 in group 3, 1382 ± 2701 in group 4, 25,811 ± 19,107 in group 5 and 17,817 ± 11,924 in group 6. Significantly higher number of cycles to failure were indicated for group 1 versus group 2 (p = 0.021), group 3 versus group 4 (p = 0.007), and in group 6 versus group 4 (p = 0.010). Conclusions: From a biomechanical perspective, proper centre-centre implant positioning in the femoral head is of utmost importance. In cases when this is not achievable in a clinical setting, a helical blade is more forgiving in the less ideal (anterior) malposition when compared to a screw, the latter revealing unacceptable low resistance to femoral head rotation and early failure. Cement augmentation of both off-centre implanted helical blade and screw head elements increases their resistance against failure; however, this effect might be redundant for helical blades and is highly unpredictable for screws.

Trochanteric Femur Fractures: Application of Skeletal Traction during Surgery Does Not Alter Soft-Tissue Microcirculation.

Background and Objectives: Wound infections provoked by alterations in microcirculation are major complications in the treatment of trochanteric femur fractures. Surgical fracture fixation on a traction table is the gold standard for treatment, but the effect on tissue microcirculation is unknown. Microcirculation could be impaired by the pull on the soft-tissue or by a release of vasoactive factors. We hypothesized that intraoperative traction impairs soft-tissue microcirculation. Materials and Methods: In 22 patients (14 women, eight men), average age 78 years (range 36-96 ± 14), with trochanteric femur fractures, non-invasive laser-Doppler spectrophotometry was used to assess oxygen saturation, hemoglobin content, and blood flow in the skin and subcutaneous tissue before and after application of traction. Measurements were recorded in nine locations around the greater trochanter at a depth of 2, 8, and 15 mm before and after fracture reduction by traction. Results: No differences were found in any depth with traction compared to without (oxygen saturation: p = 0.751, p = 0.308, and p = 0.955, haemoglobin content: p = 0.651, p = 0.928, and p = 0.926, blood flow: p = 0.829, p = 0.866, and p = 0.411). Conclusion: In this pilot study, the application of traction does not affect skin and subcutaneous microcirculation in the surgery of proximal femur fractures.

Reduced pre-operative skin oxygen saturation predicts revision after open reduction and internal fixation in calcaneal fractures : A reduced pre-operative oxygen saturation as measured by laser-Doppler spectrophotometry in 8 mm depth is associated with revision surgery after open reduction and internal fixation of calcaneal fractures through an extended lateral approach.

PURPOSE: To assess which pre-operative parameters correlate with wound revisions after an extended lateral approach to the calcaneus. METHODS: Pre-operative laser-Doppler spectrophotometry was applied in patients undergoing open reduction and internal fixation. The number of wound revisions was recorded during pos-toperative follow-up. Spearman rho analysis was used to identify factors associated with wound revision and receiver operator characteristics curves were calculated for the identified factors. RESULTS: Thirty-four patients (29 men, 5 women; 37 calcanei) with a mean patient age of 43 ± 14 years were analyzed. The minimal oxygen saturation value at the five measurement locations as well as the minimal value for flow correlated negatively with wound revisions (p value = 0.025 and 0.038, respectively). The area under the curve for the pre-operative minimal value of oxygen saturation was 0.841 (95%CI 0.64-1.00, p = 0.028), indicating a good accuracy as a test to predict wound revision. CONCLUSION: A pre-operative oxygen saturation of at least 20.5% across five measurement points along the anticipated incision identified all patients not needing a wound revision (negative predictive value 100%). On the other hand, patients with at least one measurement below 20.5% were at risk for wound revision surgery (sensitivity 100%, specificity 48.5%). ClinicalTrials.gov NCT01264146.

Biochemical MRI With dGEMRIC Corresponds to 3D-CT Based Impingement Location for Detection of Acetabular Cartilage Damage in FAI Patients.

BACKGROUND: Anterior femoroacetabular impingement (FAI) is associated with labral tears and acetabular cartilage damage in athletic and young patients. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is an imaging method for detecting early damage to cartilage. PURPOSE: We evaluated the following questions: (1) What is the sensitivity and specificity of morphological magnetic resonance imaging (MRI) and dGEMRIC for detecting cartilage damage? Do the mean acetabular and femoral dGEMRIC indices differ between (2) superior acetabular clock positions with and without impingement and (3) between cam- and pincer-type FAI? STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: This was a retrospective comparative study of 21 hips (20 patients with symptomatic anterior FAI) without osteoarthritis on anteroposterior radiographs. Morphological MRI and dGEMRIC (3.0-T, 3-dimensional [3D] T1 maps, dual-flip angle technique) of the same hip joint were compared. Intraoperative acetabular cartilage damage was assessed in patients who underwent surgical treatment. Computed tomography (CT)-based 3D bone models of the same hip joint were used as the gold standard for the detection of impingement, and dGEMRIC indices and zones of morphologic damage were compared with the CT-based impingement zones. RESULTS: Of the 21 hips, 10 had cam-type FAI and 8 had pincer-type FAI according to radiographs. The mean age was 30 ± 9 years (range, 17-48 years), 71% were female, and surgical treatment was performed in 52%. We found a significantly higher sensitivity (69%) for dGEMRIC compared with morphological MRI (42%) in the detection of cartilage damage (P < .001). The specificity of dGEMRIC was 83% and accuracy was 78%. The mean peripheral acetabular and femoral dGEMRIC indices for clock positions with impingement (485 ± 141 and 440 ± 121 ms) were significantly lower compared with clock positions without impingement (596 ± 183 and 534 ± 129 ms) (P < .001). Hips with cam-type FAI had significantly lower acetabular dGEMRIC indices compared with hips with pincer-type FAI on the anterosuperior clock positions (1 to 3 o'clock) (P = .018). CONCLUSION: MRI with dGEMRIC was more sensitive than morphological MRI, and lower dGEMRIC values were found for clock positions with impingement as detected on 3D-CT. This could aid in patient-specific diagnosis of FAI, preoperative patient selection, and surgical decision making to identify patients with cartilage damage who are at risk for inferior outcomes after hip arthroscopy.

Good Outcome Scores and Low Conversion Rate to THA 10 Years After Hip Arthroscopy for the Treatment of Femoroacetabular Impingement.

BACKGROUND: Arthroscopic treatment of symptomatic femoroacetabular impingement (FAI) has promising short-term to mid-term results. In addition to treating acute pain or impaired function, the goal of hip-preserving surgery is to achieve a lasting improvement of hip function and to prevent the development of osteoarthritis. Long-term results are necessary to evaluate the effectiveness of surgical treatment and to further improve results by identifying factors associated with conversion to THA. QUESTIONS/PURPOSES: (1) How do the Merle d'Aubigné-Postel scores change from before surgery to follow-up of at least 10 years in patients undergoing hip arthroscopy for the treatment of FAI? (2) What is the cumulative 10-year survival rate of hips with the endpoints of conversion to THA or a Merle d'Aubigné-Postel score less than 15? (3) Which factors are associated with conversion to THA? METHODS: Between 2003 and 2008, we treated 63 patients (65 hips) for symptomatic FAI with hip arthroscopy at our institution. During that period, the indications for using arthroscopy were correction of anterior cam morphology and anterolateral rim trimming with debridement or reattachment of the labrum. We excluded patients who were younger than 16 years and those who had previous trauma or surgery of the hip. Based on that, 60 patients (62 hips) were eligible. A further 17% (10 of 60) of patients were excluded because the treatment was purely symptomatic without treatment of cam- and/or pincer-type morphology. Of the 50 patients (52 hips) included in the study, 2% (1) of patients were lost before the minimum study follow-up of 10 years, leaving 49 patients (51 hips) for analysis. The median (range) follow-up was 11 years (10 to 17). The median age at surgery was 33 years (16 to 63). Ninety percent (45 of 50) of patients were women. Of the 52 hips, 75% (39 of 52) underwent cam resection (femoral offset correction), 8% (4 of 52) underwent acetabular rim trimming, and 17% (9 of 52) had both procedures. Additionally, in 35% (18 of 52) of hips the labrum was debrided, in 31% (16 of 52) it was resected, and in 10% (5 of 52) of hips the labrum was reattached. The primary clinical outcome measurements were conversion to THA and the Merle d'Aubigné-Postel score. Kaplan-Meier survivorship and Cox regression analyses were performed with endpoints being conversion to THA or Merle d'Aubigné-Postel score less than 15 points. RESULTS: The clinical result at 10 years of follow-up was good. The median improvement of the Merle d'Aubigné-Postel score was 3 points (interquartile range 2 to 4), to a median score at last follow-up of 17 points (range 10 to 18). The cumulative 10-year survival rate was 92% (95% CI 85% to 99%) with the endpoints of conversion to THA or Merle d'Aubigné-Postel score less than 15. Factors associated with conversion to THA were each year of advancing age at the time of surgery (hazard ratio 1.1 [95% CI 1.0 to 1.3]; p = 0.01) and preoperative Tönnis Grade 1 compared with Tönnis Grade 0 (no sign of arthritis; HR 17 [95% CI 1.8 to 166]; p = 0.01). CONCLUSION: In this series, more than 90% of patients retained their native hips and reported good patient-reported outcome scores at least 10 years after arthroscopic treatment of symptomatic FAI. Younger patients fared better in this series, as did hips without signs of osteoarthritis. Future studies with prospective comparisons of treatment groups are needed to determine how best to treat complex impingement morphologies. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Improved Cartilage Quality on Delayed Gadolinium-Enhanced MRI of Hip Cartilage after Subchondral Drilling of Acetabular Cartilage Flaps in Femoroacetabular Impingement Surgery at Minimum 5-Year Follow-Up.

OBJECTIVE: To assess whether subchondral drilling of acetabular cartilage flaps during femoroacetabular impingement (FAI) surgery improves (1) acetabular dGEMRIC indices and (2) morphologic magnetic resonance imaging (MRI) scores, compared with hips in which no additional treatment of cartilage lesions had been performed; and (3) whether global dGEMRIC indices and MRI scores correlate. DESIGN: Prospective cohort study of consecutive patients with symptomatic FAI treated with open surgery between 2000 and 2007. Patients with subchondral drilling of acetabular cartilage flaps were allocated to the study group, those without drilling to the control group. All patients underwent indirect 3-T MR arthrography to assess cartilage quality by dGEMRIC indices and a semiquantitative morphologic MRI score at minimum 5 years after surgery. dGEMRIC indices and morphologic MRI scores were compared between and among groups using analysis of covariance/paired t tests. RESULTS: No significant difference was found between the global dGEMRIC indices of the study group (449 ± 147 ms, 95% CI 432-466 ms) and the control group (428 ± 143 ms, 95% CI 416-442 ms; P = 0.235). In regions with cartilage flaps, the study group showed higher dGEMRIC indices (472 ± 160 ms, 95% CI 433-510 ms) compared with the control group (390 ± 122 ms, 95% CI 367-413 ms; P < 0.001). No significant differences were found for the morphologic MRI scores. A strong inversely linear correlation between the dGEMRIC indices and the morphologic MRI scores (r = -0.727, P < 0.001) was observed. CONCLUSIONS: Treatment of acetabular cartilage flaps with subchondral drilling leads to better cartilage quality in regions with cartilage flaps at minimum 5 years of follow-up.

The Ganz acetabular reinforcement ring shows excellent long-term results when used as a primary implant: a retrospective analysis of two hundred and forty primary total hip arthroplasties with a minimum follow-up of twenty years.

PURPOSE: The acetabular reinforcement ring with a hook (ARRH) has been designed for acetabular total hip arthroplasty (THA) revision. Additionally, the ARRH offers several advantages when used as a primary implant especially in cases with altered acetabular morphology. The implant facilitates anatomic positioning by placing the hook around the teardrop and provides a homogenous base for cementing the polyethylene cup. Therefore, the implant has been widely used in primary total hip arthroplasty at our institution. The present study reports the long-term outcome of the ARRH after a minimum follow-up of 20 years. METHODS: Two hundred and ten patients with 240 primary THAs performed between April 1987 and December 1991 using the ARRH were retrospectively reviewed after a minimum follow-up of 20 years. Twenty-three of 240 hips were lost to follow-up, 110 patients with 124 THAs had deceased without having a revision surgery performed. This left 93 hips for final evaluation. Of those, 75 hips were assessed clinically and radiographically after a mean follow-up of 23.1 years (range 21.1-26.1 years). In 18 cases, clinical and radiographic assessment was omitted because implant revision had been performed prior to the follow-up investigation. The primary endpoint was defined as revision for aseptic loosening. RESULTS: Out of the 93 hips available for final evaluation, 14 hips were revised for aseptic loosening; another four were revised for other reasons (deep infection n = 2, recurrent dislocation n = 2). The survival probability of the cup was 0.96 (95% confidence interval 0.93-0.99) after 20 years with aseptic loosening as endpoint. Radiographic analysis of the surviving 75 hips showed at least one sign of radiographic loosening in 24 hips. The mean Merle d'Aubigne score increased from 8 points pre-operatively to 15 points at final follow-up (7.5 ± 1.8 vs 15.0 ± 2.3, p < 0.001). The mean HHS was 85 ± 14 at final follow-up. Radiographic loosening did not correlate with the clinical outcome. CONCLUSIONS: The long-term results of the ARRH in primary THA are comparable to results with standard cemented cups and modern cementless cups. We believe that the ARRH is a versatile implant for primary THA, especially in cases with limited acetabular coverage and altered acetabular bone stock where the ARRH provides sufficient structural support for a cemented cup.

Subchondral drilling for chondral flaps reduces the risk of total hip arthroplasty in femoroacetabular impingement surgery at minimum five years follow-up.

INTRODUCTION:: The best treatment of acetabular chondral flaps during surgery for femoroacetabular impingement (FAI) is unknown. We asked if subchondral drilling improves clinical and radiographic outcome and if there are factors predicting failure. METHODS:: We treated 79 patients with symptomatic FAI and acetabular chondral flaps with surgical hip dislocation between January 2000 and December 2007. Exclusion of all patients with previous hip pathology or trauma resulted in 62 patients (80 hips). The chondral flap was slightly debrided in 43 patients/51 hips (control group). In 28 patients/29 hips (study group), additional osseous drilling was performed. 4 patients (5 hips, 6%) were lost to follow-up. Mean follow-up was 9 years (5-13 years). The groups did not differ in demographic data, radiographic parameters or follow-up. Clinical outcome was assessed with the Merle d'Aubigné score, modified Harris Hip Score and University of California Los Angeles activity score and progression of osteoarthritis with the Tönnis grade. RESULTS:: No patient underwent conversion to total hip arthroplasty (THA) in the drilling group compared to 7 patients (8 hips, 16%) in the control group ( p = 0.005); in the remaining hips, clinical scores and progression of Tönnis grade did not differ. Increased acetabular coverage, age and body mass index were univariate predictive factors for conversion to THA. No drilling was as an independent predictive factor for conversion to THA (hazard ratio 58.07, p = 0.009). CONCLUSION:: Subchondral drilling under acetabular chondral flaps during surgical treatment of FAI is an effective procedure to reduce the rate of conversion to THA.

How Does the dGEMRIC Index Change After Surgical Treatment for FAI? A Prospective Controlled Study: Preliminary Results.

BACKGROUND: Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) allows an objective, noninvasive, and longitudinal quantification of biochemical cartilage properties. Although dGEMRIC has been used to monitor the course of cartilage degeneration after periacetabular osteotomy (PAO) for correction of hip dysplasia, such longitudinal data are currently lacking for femoroacetabular impingement (FAI). QUESTIONS/PURPOSES: (1) How does the mean acetabular and femoral dGEMRIC index change after surgery for FAI at 1-year followup compared with a similar group of patients with FAI treated without surgery? (2) Does the regional distribution of the acetabular and femoral dGEMRIC index change for the two groups over time? (3) Is there a correlation between the baseline dGEMRIC index and the change of patient-reported outcome measures (PROMs) at 1-year followup? (4) Among those treated surgically, can dGEMRIC indices distinguish between intact and degenerated cartilage? METHODS: We performed a prospective, comparative, nonrandomized, longitudinal study. At the time of enrollment, the patients' decision whether to undergo surgery or choose nonoperative treatment was not made yet. Thirty-nine patients (40 hips) who underwent either joint-preserving surgery for FAI (20 hips) or nonoperative treatment (20 hips) were included. The two groups did not differ regarding Tönnis osteoarthritis score, preoperative PROMs, or baseline dGEMRIC indices. There were more women (60% versus 30%, p = 0.003) in the nonoperative group and patients were older (36 ± 8 years versus 30 ± 8 years, p = 0.026) and had lower alpha angles (65° ± 10° versus 73° ± 12°, p = 0.022) compared with the operative group. We used a 3.0-T scanner and a three-dimensional dual flip-angle gradient-echo technique for the dGEMRIC technique for the baseline and the 1-year followup measurements. dGEMRIC indices of femoral and acetabular cartilage were measured separately on the initial and followup radial dGEMRIC reformats in direct comparison with morphologic radial images. Regions of interest were placed manually peripherally and centrally within the cartilage based on anatomic landmarks at the clockface positions. The WOMAC, the Hip disability and Osteoarthritis Outcome Score, and the modified Harris hip score were used as PROMs. Among those treated surgically, the intraoperative damage according to the Beck grading was recorded and compared with the baseline dGEMRIC indices. RESULTS: Although both the operative and the nonoperative groups experienced decreased dGEMRIC indices, the declines were more pronounced in the operative group (-96 ± 112 ms versus -16 ± 101 ms on the acetabular side and -96 ± 123 ms versus -21 ± 83 ms on the femoral side in the operative and nonoperative groups, respectively; p < 0.001 for both). Patients undergoing hip arthroscopy and surgical hip dislocation experienced decreased dGEMRIC indices; the decline in femoral dGEMRIC indices was more pronounced in hips after surgical hip dislocation (-120 ± 137 ms versus -61 ± 89 ms, p = 0.002). In the operative group a decline in dGEMRIC indices was observed in 43 of 44 regions over time. In the nonoperative group a decline in dGEMRIC indices was observed in four of 44 regions over time. The strongest correlation among patients treated surgically was found between the change in WOMAC and baseline dGEMRIC indices for the entire joint (R = 0.788, p < 0.001). Among those treated nonoperatively, no correlation between baseline dGEMRIC indices and change in PROMs was found. In the posterosuperior quadrant, the dGEMRIC index was higher for patients with intact cartilage compared with hips with chondral lesions (592 ± 203 ms versus 444 ± 205 ms, p < 0.001). CONCLUSIONS: We found a decline in acetabular, femoral, and regional dGEMRIC indices for the surgically treated group at 1-year followup despite an improvement in all PROMs. We observed a similar but less pronounced decrease in the dGEMRIC index in symptomatic patients without surgical treatment indicating continuous cartilage degeneration. Although treatment of FAI is intended to alter the forces acting across the hip by eliminating impingement, its effects on cartilage biology are not clear. dGEMRIC provides a noninvasive method of assessing these effects. Longer term studies will be needed to determine whether the matrix changes of the bradytrophic cartilage seen here are permanent or clinically important. LEVEL OF EVIDENCE: Level II, therapeutic study.

Twelve percent of hips with a primary cam deformity exhibit a slip-like morphology resembling sequelae of slipped capital femoral epiphysis.

BACKGROUND: In some hips with cam-type femoroacetabular impingement (FAI), we observed a morphology resembling a more subtle form of slipped capital femoral epiphysis (SCFE). Theoretically, the morphology in these hips should differ from hips with a primary cam-type deformity. QUESTIONS/PURPOSES: We asked if (1) head-neck offset; (2) epiphyseal angle; and (3) tilt angle differ among hips with a slip-like morphology, idiopathic cam, hips after in situ pinning of SCFE, and normal hips; and (4) what is the prevalence of a slip-like morphology among cam-type hips? METHODS: We retrospectively compared the three-dimensional anatomy of hips with a slip-like morphology (29 hips), in situ pinning for SCFE (eight hips), idiopathic cam deformity (171 hips), and 30 normal hips using radial MRI arthrography. Normal hips were derived from 17 asymptomatic volunteers. All other hips were recruited from a series of 277 hips (243 patients) seen at a specialized academic hip center between 2006 and 2010. Forty-one hips with isolated pincer deformity were excluded. Thirty-six of 236 hips had a known cause of cam impingement (secondary cam), including eight hips after in situ pinning of SCFE (postslip group). The 200 hips with a primary cam were separated in hips with a slip-like morphology (combination of positive fovea sign [if the neck axis did not intersect with the fovea capitis] and a tilt angle [between the neck axis and perpendicular to the basis of the epiphysis] exceeding 4°) and hips with an idiopathic cam. We evaluated offset ratio, epiphyseal angle (angle between the neck axis and line connecting the center of the femoral head and the point where the physis meets the articular surface), and tilt angle circumferentially around the femoral head-neck axis. Prevalence of slip-like morphology was determined based on the total of 236 hips with cam deformities. RESULTS: Offset ratio was decreased anterosuperiorly in idiopathic cam, slip-like, and postslip (eg, 1 o'clock position with a mean offset ranging from 0.00 to 0.14; p < 0.001 for all groups) compared with normal hips (0.25 ± 0.06 [95% confidence interval, 0.13-0.37]) and increased posteroinferiorly in slip-like (eg, 8 o'clock position, 0.5 ± 0.09 [0.32-0.68]; p < 0.001) and postslip groups (0.55 ± 0.12 [0.32-0.78]; p < 0.001) and did not differ in idiopathic cam (0.32 ± 0.09 [0.15-0.49]; p = 0.323) compared with normal (0.31 ± 0.07 [0.18-0.44]) groups. Epiphyseal angle was increased anterosuperiorly in the slip-like (eg, 1 o'clock position, 70° ± 9° [51°-88°]; p < 0.001) and postslip groups (75° ± 13° [49°-100°]; p = 0.008) and decreased in idiopathic cam (50° ± 8° [35°-65°]; p < 0.001) compared with normal hips (58° ± 8° [43°-74°]). Posteroinferiorly, epiphyseal angle was decreased in slip-like (eg, 8 o'clock position, 54° ± 10° [34°-74°]; p < 0.001) and postslip (44° ± 11° [23°-65°]; p < 0.001) groups and did not differ in idiopathic cam (76° ± 8° [61°-91°]; p = 0.099) compared with normal (73° ± 7° [59°-88°]) groups. Tilt angle increased in slip-like (eg, 2/8 o'clock position, 14° ± 8° [-1° to 30°]; p < 0.001) and postslip hips (29° ± 10° [9°-48°]; p < 0.001) and decreased in hips with idiopathic cam (-7° ± 5° [-17° to 4°]; p < 0.001) compared with normal (-1° ± 5° [-10° to 8°]) hips. The prevalence of a slip-like morphology was 12%. CONCLUSIONS: The slip-like morphology is the second most frequent pathomorphology in hips with primary cam deformity. MRI arthrography of the hip allows identifying a slip-like morphology, which resembles hips after in situ pinning of SCFE and distinctly differs from hips with idiopathic cam. These results support previous studies reporting that SCFE might be a risk factor for cam-type FAI.

Diagnosis and management of developmental dysplasia of the hip from triradiate closure through young adulthood.

The current treatment of painful hip dysplasia in the mature skeleton is based on acetabular reorientation. Reorientation procedures attempt to optimize the anatomic position of the hyaline cartilage of the femoral head and acetabulum in regard to mechanical loading. Because the Bernese periacetabular osteotomy is a versatile technique for acetabular reorientation, it is helpful to understand the approach and be familiar with the criteria for an optimal surgical correction. The femoral side bears stigmata of hip dysplasia that may require surgical correction. Improvement of the head-neck offset to avoid femoroacetabular impingement has become routine in many hips treated with periacetabular osteotomy. In addition, intertrochanteric osteotomies can help improve joint congruency and normalize the femoral neck orientation. Other new surgical techniques allow trimming or reducing a severely deformed head, performing a relative neck lengthening, and trimming or distalizing the greater trochanter. An increasing number of studies have reported good long-term results after acetabular reorientation procedures, with expected joint preservation rates ranging from 80% to 90% at the 10-year follow-up and 60% to 70% at the 20-year follow-up. An ideal candidate is younger than 30 years, with no preoperative signs of osteoarthritis. Predicted joint preservation in these patients is approximately 90% at the 20-year follow-up. Recent evidence indicates that additional correction of an aspheric head may further improve results.

Using micropower impulse radar technology to screen for pneumothorax: an international bi-institutional study.

BACKGROUND: Pneumothoraces (PTXs) are a common entity in thoracic trauma. Micropower impulse radar (MIR) has been able to detect PTXs in surgical patients. However, this technology has not been tested previously on trauma patients. The purpose of this study was to determine the sensitivity and specificity of MIR to detect clinically significant PTXs. We hypothesized that MIR technology can effectively screen trauma patients for clinically significant PTXs. METHODS: This was a prospective observational study in Level I trauma centers in Boston, Massachusetts, and Bern, Switzerland. All trauma patients undergoing a chest computed tomographic (CT) scan were eligible for the study. Consent was obtained, and readings were performed within 30 minutes before or after the CT scan. The patients had eight lung fields tested (four on each side). The qualitative and quantitative MIR results were blinded and stored on the device. We then compared the results of the MIR to the CT scan and the need for chest tube drainage. We defined PTXs as clinically significant if they required a chest tube. RESULTS: Seventy-five patients were enrolled, with a mean age of 46 ± 16 years. Eighty-four percent were male. The screening test took approximately 1 minute. All but two patients had blunt chest trauma. Six true-positives, 6 false-positives, 63 true-negatives, and 0 false-negatives resulted in an overall sensitivity of 100%. CONCLUSION: MIR is an easy to use handheld technology that effectively screened patients for clinically significant PTXs, with a sensitivity and negative predictive value of 100%. MIR may be used for rapid, repeatable, and ongoing surveillance of trauma patients. LEVEL OF EVIDENCE: Diagnostic study, level III.