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Occult periprosthetic fractures have been defined as a fracture only visible on postoperative CT scans but not on postoperative plain radiography after an uneventful surgery without intraoperative fracture. The fracture rate for hemispherical and peripheral self-locking cups has been described as 8.4%. We retrospectively analyzed postoperative CT scans after primary THA to clear the question whether such occult periprosthetic fractures of the acetabulum require particular treatment strategy. Between 2014 and 2018 we identified 115 CT scans of 114 patients after primary cementless THA with elliptical cups using a direct anterior approach. The CT scans were obtained as part of other investigations. Localization of the fracture, patients demographics, clinical (WOMAC, Harris Hip Score) and radiological outcome were analyzed. Fracture and non-Fracture group were compared with regard to demographics and short-term outcome after 1 year. Four occult fractures (3.5%) were identified. Three fractures involved the posterior wall. All patients had an uneventful routine postoperative rehabilitation. Patients with occult fractures showed similar post- operative HHS and WOMAC scores at 3 (HHS p = 0.576, WOMAC p = 0.128) and 12 (HHS p = 0.479, WOMAC p = 0.588) months. There were no cup loosening nor radiolucent lines at latest follow-up (mean FU 22 months, range 12-34 months). Clinical and radiological short-term outcome was not impaired by the occurrence of an occult periprosthetic fracture of the acetabulum. The incidental detection of an occult periprosthetic fracture of the acetabulum does not seem to oblige the surgeon to adapt the postoperative regime.

Introduction:Femoral rotational osteotomies can be a treatment option for symptomatic femoral maltorsion. This study investigated the clinical and radiological results of subtrochanteric rotational osteotomy and its potential adverse effects, particularly on patellofemoral stability and geometry.Methods:Retrospective consecutive series of patients undergoing subtrochanteric rotational osteotomy with hip arthroscopy. 25 hips, 18 with decreased (⩽4°), 7 with increased (⩾28°) femoral torsion (FT), were analysed. Mean follow-up was 37 months. Subjective Hip value (SHV), WOMAC and Harris Hip Score (HHS), hip range of motion, asymmetries in foot position during gait as well as patellofemoral instability were the outcome measures. Femoral and tibial torsion as well as morphological signs of patella maltracking (TTTG, patellar tilt and lateralisation) were measured on MRI.Results:SHV improved from 52% to 72% ( p = 0.002), WOMAC from 3 to 1 ( p 0.08), patellar tilt ( p > 0.09) and lateralisation ( p > 0.26) did not differ. No complications occurred.Conclusions:Subtrochanteric rotational osteotomy with hip arthroscopy improves the hip subjectively without leading to objective patellofemoral instability nor changes in the patellofemoral geometry compared to contralateral side. The technique of subtrochanteric rotational osteotomy is safe and reliable.

The aim of this study was to evaluate whether new tissue formation occurs after labral debridement/excision, and, if so, which morphological features are typical for a neo-labrum. The authors further compared the findings after labrum resection with those seen after labrum refixation. Patients with femoroacetabular impingement who underwent hip arthroscopy or surgical hip dislocation to address a labrum pathology were retrospectively included, and postoperative magnetic resonance arthrography studies were assessed. Forty-two patients had undergone either labrum resection (n=25) or refixation (n=17), performed arthroscopically (47.6%) or via surgical hip dislocation (52.4%). In the subgroup of patients after debridement/resection, there was anterosuperior/superior scar tissue in 83.5%, with amorphous configuration in 92%, irregular surface in approximately two-thirds of the cases, and a mean±SD thickness of 7.0±2.7 mm. A labrum-like shape of the scar plate was seen in 7.7%. Regarding the subgroup of patients who had undergone labral refixation, an irregular or rounded labrum shape was noted in 26.5% and 51.3% of cases, respectively, with a triangular shape in less than one-fourth of cases. Labrum re-tears (35.7%) were mainly observed at the base (71.7%), rather than within the labral substance (28.4%). New tissue formation can be observed in the majority of cases after excision of the hip labrum, with amorphous and irregular surface configuration compared with a native labrum. This new tissue should therefore be referred to as scar tissue rather than as neo-labrum. Whether scar tissue is inferior to a refixed labrum needs to be further elucidated in follow-up studies. [ Orthopedics . 2021;44(4):e607–e613.]

The goal of periacetabular osteotomy (PAO) is to reorient the acetabulum in a more physiological position. Its realization remains challenging regarding the final position of the acetabulum. Assistance with custom cutting- and reorientation-guides would thus be very helpful. Our purpose is to present a pilot study on such guides. Eight cadaveric hemipelvis were scanned using CT. After segmentation, 3D models of each specimen were created, a PAO was virtually performed and reorientation of the acetabula were defined. A specific guide was designed aiming to assist in iliac, posterior column and superior pubic ramus cuts as well as in acetabulum reorientation. Furthermore, the acetabular position was planned. Three-dimensional printed guides were used to perform PAO using the modified Smith-Peterson approach. The post-operative CT images and virtually planned acetabulum reorientation were compared in terms of acetabular index (AC), lateral centre edge angle (LCE), acetabular anteversion angle (AcetAV). There was no intra-articular or posterior column fracture seen. Two cadavers showed very low bone quality with insufficient stability of fixation and were excluded from further analysis. Correlation between the post-operative result and planning of the six included cadavers revealed the following mean deviations: 5° (SD ±3°) for AC angle, 6° (SD ±4°) for LCE angle and 15° (SD ±11°) for AcetAV angle. The use of 3D cutting and reorientation blocks for PAO was possible through a modified Smith-Peterson approach and revealed accurate fit to bone, accurate positioning of the osteotomies and acceptable planned corrections in cadavers with good bone quality.

The direct minimally invasive anterior approach (DMIAA) in total hip arthroplasty (THA) is widely accepted. In our department the DMIAA according to Rachbauer together with the Trident cup and Accolade stem was introduced in 2004. The purpose of the study was to demonstrate the five-year results and to analyze the learning curve of a new introduced approach.Between July 2004 and May 2006, a consecutive series of 151 THA in 147 patients was retrospectively analyzed. All patients were planned to received a THA with the Accolade/Trident implant system using the DMIAA without traction table. Clinical and radiographic data, complications and survivorship were documented with a follow-up of at least 5 years.Regarding cup implantation, there were 11 (7.3%) failed intentions to treat due to missing pressfit (8 cases) and acetabular floor perforation (3 cases). No failed intentions to treat occurred during stem implantation. Total implant survival after 5 years follow-up after exclusion of 11 cases with failed intention to treat (N=140) was 96.9% (SD 1.4; CI 94.3-99.6). After exclusion of the failed intentions to treat (N=140, N=4 in the first 20 cases), there was significant (p0.001) difference between the first 16 implants with a 5 year-survival of 83.2% (SD 8.6; CI 66.4-100) and 95.7% (SD 0.9; CI 93.9-97.5) for the following 124 implants. Radiolucent lines were observed in Gruen zone 1 in 3.3% and in Gruen zone 1 and 2 in 1.1%.THA with Accolade/Trident using the DMIAA without traction table according to Rachbauer temporary exposed patients to a higher risk of implant revisions, which was normalized after the first 20 cases. Results of the learning curve are comparable to other techniques using an orthopaedic traction table. After the typical learning curve, the rate of 5 years implant failure is in accordance with the registry data for non-cemented implants. The Accolade stem showed minimal radiographic signs of radiolucency.IV, retrospective, consecutive case series.

PURPOSE To assess construct and face validity of a novel virtual reality-based hip arthroscopy simulator using the previously validated Arthroscopic Surgery Skills Evaluation Tool (ASSET), metric parameters, and a questionnaire. METHODS Metric parameters including task completion time, camera path, and grasper path were recorded, and the ASSET score was used to assess construct validity. Face validity was evaluated using a questionnaire. RESULTS Nine hip arthroscopy experts, of whom the majority performed more than 200 procedures (age, 48 ± 7.3; range, 38-61 years; 8 men, 1 woman), and 33 nonexperts (age, 33 ± 7.9; range, 26-62 years; 25 men, 8 women) performed 3 individual tasks on a virtual reality-based arthroscopy simulator of a left hip. The ASSET global rating scale showed a statistically significant difference between the hip arthroscopy expert and the nonexpert group, indicating strong construct validity (25.0 in the expert group, range, 17-34, versus 15.30 in the nonexpert group, range, 8-30 [P < .001], respectively). This also applied to most metric parameters recorded by the simulator. The simulator also demonstrated high face validity. The overall impression in terms of realism was graded "completely realistic" by 17% and "close to realistic" by 62% of participants. CONCLUSIONS The tested simulator demonstrated high construct and face validity. CLINICAL RELEVANCE This study demonstrates the construct and face validity of a novel hip arthroscopy simulator. The device proved to be an adequate model for the simulation of some arthroscopic procedures of the hip.

Background Leg length discrepancy (LLD) is common after total hip arthroplasty (THA) with a plethora of clinical consequences. The associations between symptomatic (sLLD; disturbing perception of anatomical leg length discrepancy), anatomical (aLLD; side difference in leg length between the center of rotation of the hip and the center of the ankle joint) and intraarticular (iLLD; side difference between the tear drop figure and the most prominent point of the trochanter minor) LLD and lower back have not yet been reported in the literature. We performed a retrospective study to answer if postoperative (1) symptomatic LLD, (2) anatomic LLD, and (3) a change in intraarticular leg length are associated with lower back pain in patients undergoing THA. Further, we aimed to answer (4) whether symptomatic LLD is associated with the magnitude of anatomical LLD and the change in intraarticular leg length. Hypothesis LLD after THA is associated with lower back pain. Materials and methods Seventy-nine consecutive patients were retrospectively analyzed for the presence of aLLD and iLLD using EOS™ and X-rays, and were interviewed for the presence of sLLD and lower back pain using a questionnaire 5 years after primary THA. Results Postoperative new onset of lower back pain was reported by 9 (11%) patients. Twenty (25%) patients reported sLLD. Anatomical LLD > 5 mm was present in 44 (56%) (median 8.0 (IQR −3.0 to 12.0; range −22 to 22) mm) and > 10 mm in 17 (22%) (median 12.0 (IQR 11.0 to 16.5; range −22 to 22) mm) patients. iLLD changed > 5 mm in 44 (56%) (median 8.5 (IQR 7.0 to 10.0; range −8 to 18) mm) and > 10 mm in 10 (13%) (median 14.0 (IQR 12.5 to 14.5; range 11 to 18) mm). New onset lower back pain was associated with sLLD (p = 0.002) but not with aLLD or iLLD. Patients without preoperative lower back pain had a statistically significant association between presence of sLLD and an aLLD of > 10 mm (p = 0.01). Conclusions Symptomatic LLD after primary THA is associated with postoperative new onset of lower back pain irrespective of the magnitude of LLD. In patients without lower back pain prior to THA, symptomatic LLD is associated with anatomical LLD of more than 10 mm. Level of evidence IV.

This study aimed to compare patient outcomes and residual complains after hip arthroscopy (HAS) and total hip arthroplasty (THA) to improve patient counseling. It includes 140 hips/129 HAS-patients and 77 hips/62 THA-patients aged 40 to 55 years with a BMI under 30. All patients underwent primary HAS or primary THA in our hospital from 2007 until 2014. Exclusion criteria were a history of prior hip surgery or suffering sequels of childhood's hip disease, systemic inflammatory disease or avascular hip osteonecrosis. Outcome measures were WOMAC, subjective hip value, residual complains, the need of infiltrations and the complication and conversion rate. Patient data and scores were collected pre-operative, after one year and at the last follow-up. Scores indicated significant patient benefits in both groups (p

Purpose To determine and compare the frequency of imaging abnormalities in asymptomatic and symptomatic patients after arthroscopic hip surgery. Materials and Methods This study was approved by the institutional review board. Informed consent was obtained from all patients. Thirty-four patients (17 asymptomatic and 17 symptomatic patients) underwent 1.5-T magnetic resonance (MR) arthrography of the hip 1 year after arthroscopic treatment of femoroacetabular impingement. Two readers independently analyzed all MR arthrographic images for the presence of abnormal imaging findings, including capsular adhesions at the femoral neck, obliteration of the paralabral sulcus, labral defects, and defects of the hip capsule in several anatomic positions (anterior to posterior). Postoperative findings were compared with linear and generalized linear mixed-effects regression models. Results Capsular adhesions at the anterior femoral neck were present in 12 of the 34 patients (35%), and there were no differences between the groups or readers (P = .99). The paralabral sulcus was obliterated in at least one anatomic location in 94% (reader 1, 32 of 34 patients) and 100% (reader 2, 34 of 34 patients) of patients (P = .99). Residual labral tears were detected in 35% of asymptomatic patients (six of 17 patients) and 41% of symptomatic patients (seven of 17 patients) by reader 1 and in 53% of asymptomatic and symptomatic patients (nine of 17 patients in each group) by reader 2, without significant differences between the groups (P = .81). Defects of the hip capsule were more common in asymptomatic patients (77% [13 of 17 patients] for reader 1 and 53% [nine of 17 patients] for reader 2) than in symptomatic patients (59% [10 of 17 patients] for reader 1 and 47% [eight of 17 patients] for reader 2), but without significant differences (P = .33). Conclusion Obliteration of the paralabral sulcus was the most frequent finding after arthroscopic hip surgery in both asymptomatic and symptomatic patients, and capsular adhesions at the anterior femoral neck were present in 35% of patients in both groups.

As a result of the complexity and diversity of diseases in the region of the groin, differentiation of the various soft-tissue and bone pathologies remains a challenge for differential diagnosis in routine clinical practice. In the case of athletes with pain localized in the area of the groin, femoroacetabular impingement (FAI) and athlete's groin must be considered as important causes of the groin pain, whereby the common occurrence of double pathologies further complicates diagnosis. Despite the importance of groin pain and its differential diagnoses in everyday clinical practice, there has been a lack of recognized recommendations for diagnostic procedure to date. To this end, a consensus meeting was held in February 2017, in which a group composed equally of groin and hip surgeons took part. With the formulation of recommendations and the establishment of a practicable diagnostic path, colleagues that are involved in treating such patients should be sensitized to this issue and the quality of the diagnosis of groin pain improved in routine clinical practice.

Background The purpose of this study was to document complications, outcomes, and 10-year survivorship of primary total hip arthroplasty (THA) using a direct anterior approach with an uncemented, straight, hydroxyapatite-coated stem and an uncemented cup. Methods A retrospective, consecutive series of 275 primary THAs through a direct anterior approach with traction table using Medacta Versafit cup and Quadra-H stem with a minimum of 10-year follow-up was identified. The cumulative 10-year survival of the implants was estimated using Kaplan-Meier estimator. All complications, reoperations, and failures were analyzed. Subjective and clinical outcomes (Subjective Hip Value, Western Ontario and McMaster Universities Osteoarthritis Index, and Harris Hip Score) were measured. Results Of 256 patients (275 hips, 143 men and 113 women) with a mean age of 63 (range, 24-85) years, 48 (19%) patients (52 hips) deceased not related to the surgery after a mean time 49 months (range, 3-118) postoperatively. At >10-year follow-up, 9 THAs were revised. The overall implant survival rate was 96.8% (95% confidence interval, 94.4-98.7) at 10 years. One cup and 1 stem were revised because of aseptic loosening. At the last follow-up, the median Subjective Hip Value was 90% (range, 20-100), the Western Ontario and McMaster Universities Osteoarthritis Index score reached a median of 0.2 points (range, 0-6.3), and the median Harris Hip Score points was 99 (range, 29-100). Conclusion Primary THA through an anterior minimal invasive approach with the mentioned implants showed low revision rates and good to excellent clinical outcome after at least 10 years.

Background Leg length discrepancy (LLD) is common after total hip arthroplasty (THA) with a plethora of clinical consequences. The associations between symptomatic (sLLD; disturbing perception of anatomical leg length discrepancy), anatomical (aLLD; side difference in leg length between the center of rotation of the hip and the center of the ankle joint) and intraarticular (iLLD; side difference between the tear drop figure and the most prominent point of the trochanter minor) LLD and lower back have not yet been reported in the literature. We performed a retrospective study to answer if postoperative (1) symptomatic LLD, (2) anatomic LLD, and (3) a change in intraarticular leg length are associated with lower back pain in patients undergoing THA. Further, we aimed to answer (4) whether symptomatic LLD is associated with the magnitude of anatomical LLD and the change in intraarticular leg length. Hypothesis LLD after THA is associated with lower back pain. Materials and methods Seventy-nine consecutive patients were retrospectively analyzed for the presence of aLLD and iLLD using EOS™ and X-rays, and were interviewed for the presence of sLLD and lower back pain using a questionnaire 5 years after primary THA. Results Postoperative new onset of lower back pain was reported by 9 (11%) patients. Twenty (25%) patients reported sLLD. Anatomical LLD > 5 mm was present in 44 (56%) (median 8.0 (IQR -3.0 to 12.0; range -22 to 22) mm) and > 10 mm in 17 (22%) (median 12.0 (IQR 11.0 to 16.5; range -22 to 22) mm) patients. iLLD changed > 5 mm in 44 (56%) (median 8.5 (IQR 7.0 to 10.0; range -8 to 18) mm) and > 10 mm in 10 (13%) (median 14.0 (IQR 12.5 to 14.5; range 11 to 18) mm). New onset lower back pain was associated with sLLD (p = 0.002) but not with aLLD or iLLD. Patients without preoperative lower back pain had a statistically significant association between presence of sLLD and an aLLD of > 10 mm (p = 0.01). Conclusions Symptomatic LLD after primary THA is associated with postoperative new onset of lower back pain irrespective of the magnitude of LLD. In patients without lower back pain prior to THA, symptomatic LLD is associated with anatomical LLD of more than 10 mm. Level of evidence IV.

Background: Trochanteric osteotomies (TO) facilitate exposure and "true hip reconstruction” in complex primary and revision total hip arthroplasty (THA). However, non-union represents a clinically relevant complication. The purpose of the present study was to identify risk factors for trochanteric non-union. Methods: All cases of THA approached by TO during the past 10years were analyzed with respect to potential risk factors for non-union. Results: In 298 cases complete data were available for analysis. Trochanteric union occurred in 80.5%, fibrous union in 5.4% and non-union 14.1%. Risk factor analysis revealed a four times higher risk for non-union in anterior trochanteric slide osteotomies compared to extended trochanteric osteotomies and a three times higher risk in cemented versus non-cemented stems. Multiple logistic regression analysis revealed patient's age and use of cement to be independent risk factors for non-union. Conclusions: Femoral cementation and increasing age negatively influence the union of trochanteric osteotomies

Zusammenfassung: Das femoroazetabuläre Impingement (FAI) ist häufig, die geschätzte Prävalenz liegt bei 10-15%. Unsere bisher 10-jährige Erfahrung bestätigt das FAI als eine wesentliche, wenn auch nicht einzige Ursache der Koxarthrose. Isolierte azetabuläre oder femorale Fehlformen sind selten, obwohl bei Frauen die azetabuläre und bei Männern die femorale Pathomorphologie dominiert. Normalbefunde im Standardröntgen schließen ein FAI nicht aus. Symptome treten umso früher auf, je größer die Deformität und je intensiver hohe Bewegungsanforderungen gestellt werden. Die überwiegende Mehrzahl der Patienten ist

Purpose: To retrospectively evaluate the diagnostic value of 18F-FDG PET/CT in trauma patients with suspected chronic osteomyelitis. Methods: Thirty-three partial body 18F-FDG PET/CT scans were performed in 33 patients with trauma suspected of having chronic osteomyelitis. In 10 and 23 patients, infection was suspected in the axial and appendicular skeleton, respectively. In 18 patients, PET/CT was performed in the presence of metallic implants. Histopathology or bacteriological culture was used as the standard of reference. For statistical analysis, sensitivity, specificity and accuracy were calculated in relation to findings of the reference standard. Results: Of 33 PET/CT scans, 17 were true positive, 13 true negative, two false positive and one false negative. Eighteen patients had chronic osteomyelitis and 15 had no osseous infection according to the reference standard. Sensitivity, specificity and accuracy for 18F-FDG PET/CT was 94%, 87% and 91% for the whole group, 88%, 100% and 90% for the axial skeleton and 100%, 85% and 91% for the appendicular skeleton, respectively. Conclusion: 18F-FDG PET/CT is a highly sensitive and specific method for the evaluation of chronic infection in the axial and appendicular skeleton in patients with trauma. PET/CT allows precise anatomical localisation and characterisation of the infectious focus and demonstrates the extent of chronic osteomyelitis with a high degree of accuracy

Introduction: Double mobility cup systems (DMCS) have gained increasing acceptance, especially in patients at high risk for dislocation. The aim of this investigation was to analyze the frequency and indications of the DMCS use in our praxis and to evaluate dislocation and cup revision rates after a minimum follow-up of 2 years. Materials and methods: All patients implanted with a DMCS from May 2008 to August 2011 were identified from our institutional database of primary and revision THA procedures. Patient demographics, including ASA score, were recorded, along with details of the surgical procedures, indications for DMCS use, and post-operative clinical course and any complications. Radiographs were analyzed for implant positioning and radiological signs of loosening. Results: 1046 primary THA were implanted, of these 39 (4%) primary DMCS. Indications were severe neuromuscular disease (SND) (14), hip abductor degeneration (HAD) (9), cognitive dysfunction (CD) (8) and others. 345 revision THA were performed, of these 50 (14%) revision DMCS. Indications were recurrent dislocations (27), multiple prior hip surgeries (13), HAD (5), CD (3) and others. Overall dislocation rate was 2/89 (2%); both in revision THA. Overall cup revision rate was 5/89 (6%): 3 septic, 1 periprosthetic acetabular fracture, 1 "intraprosthetic dissociation”. 67 patients were available for the standardized questionnaire at a median follow-up of 43months (range 25-78). 19 patients were not available for two-year follow-up: 17 died and two were lost to follow-up. Conclusions: This study supports the use of DMCS constructs in primary and revision hip arthroplasty for specific high-risk patients. We continue to indicate DMCS in this patient group. We do caution against extending indications for DMCS to lower risk patient groups due to unknown issues surrounding wear and component longevity.

Introduction The influence of co-morbidities on complication rates and length of hospitalisation after surgery is well recognised. Clinical instruments predicting this influence, are of increasing interest. We sought to determine whether a count of a patient's preoperative pharmaceuticals would be associated to postoperative outcomes. Material and Methods In this retrospective, consecutive case series, 668 patients undergoing elective primary total hip arthroplasty (THA) were analysed. Age, gender, BMI, ASA-classification, nicotine or alcohol abuse, and the number and type of medications were documented. Results Mean age was 63 years (18-94), 53% were females. A total of 60 (8.9%) local and 19 (2.8%) systemic complications occurred during hospital stay. A total of 11 (1.6%) patients died, while 49 (7.3%) local complications occurred during the first postoperative year. Length of hospital stay, blood transfusions, and morbidity were found to be significantly related to the quantity of medications (p7 days) increased by a factor of 1.15 (CI: 1.08-1.22) with each medication, the risk of experiencing a complication within the first postoperative year was 1.19 times (CI: 1.07-1.29) for each additional medication. Type of medication also influenced morbidity: the odds ratio was 1.89 (CI: 1.05-3.41) for platelet inhibiting agents and 4.07 (CI: 1.96-8.42) for oral anticoagulants in early morbidity, which increased to 6.05 (CI:2.92-12.53) in 1-year follow-up. Conclusions The investigation illustrated the significant influence of the number and/or type of medication on complications, morbidity and prolonged hospital stay. This predictive tool may be useful, for physicians and non-health professionals, in estimating particular outcomes after elective THA.

Background The direct minimally invasive anterior approach (DMIAA) and the use of uncemented stems demonstrated an increase in intraoperative fractures in recent literature. Whether the different design of the stems additionally influences the incidence of perioperative local complications, was the goal of this study. Methods From January 2008 until June 2010, all patients undergoing primary cementless total hip arthroplasty, using a DMIAA, were consecutively included. The choice of the implant was defined by the day of operation. Age, gender, body mass index, type of prosthesis, and the practical experience of the performing surgeon were retrospectively analyzed. Of main interest were intraoperative fractures, postoperative hematoma, and wound healing. Results Six hundred forty consecutive patients (64 years [18-94], 339 female, 53%, body mass index 26) have been included. A Quadra-H stem (Medacta) was used in 457 patients (71%). In 183 (29%) patients, a short stem designed for the DMIAA (130 Fitmore, Zimmer and 53 AMIStem, Medacta) was used. We counted 34 (5.3%) intraoperative fractures (16 at the greater trochanter, 18 proximal shaft fractures), 20 (4%) hematomas, and 8 (2%) wound healing problems. The standard length stem showed more local complications (11.8% vs 4.4%) (P = .014, odds ratio 1.63, confidence interval 1.1-2.4) and significantly more (6.8% vs 1.6%) intraoperative fractures (P = .027, odds ratio 1.98, confidence interval 1.1-3.6). Conclusion The standard length stem showed more perioperative complications, especially periprosthetic fractures. It seems that these implants not only put more stress to proximal osseous structures, but there might also be more traction and irritation to the soft tissue while preparing, resulting in more hematomas and wound healing problems.

To compare soft-tissue changes after total hip arthroplasty with posterior, direct-lateral, anterolateral, or anterior surgical approaches. MRI of 120 patients after primary total hip arthroplasty (30 per approach) were included. Each MRI was assessed by two readers regarding identification of surgical access, fatty muscle atrophy (Goutallier classification), tendon quality (0 = normal, 1 = tendinopathy, 2 = partial tear, 3 = avulsion), and fluid collections. Readers were blinded to the surgical approach. Surgical access was correctly identified in all cases. The direct lateral approach showed highest Goutallier grades and tendon damage for gluteus minimus muscle (2.07-2.67 and 2.00-2.77; p = 0.017 and p = 0.001 for readers 1 and 2, respectively) and tendon (2.30/1.67; p

To assess the sustainability of our institutional bone bank, we calculated the final product cost of fresh-frozen femoral head allografts and compared these costs with the use of commercial alternatives. Between 2007 and 2010 all quantifiable costs associated with allograft donor screening, harvesting, storage, and administration of femoral head allografts retrieved from patients undergoing elective hip replacement were analysed.From 290 femoral head allografts harvested and stored as full (complete) head specimens or as two halves, 101 had to be withdrawn. In total, 104 full and 75 half heads were implanted in 152 recipients. The calculated final product costs were €1367 per full head. Compared with the use of commercially available processed allografts, a saving of at least €43 119 was realised over four-years (€10 780 per year) resulting in a cost-effective intervention at our institution. Assuming a price of between €1672 and €2149 per commercially purchased allograft, breakeven analysis revealed that implanting between 34 and 63 allografts per year equated to the total cost of bone banking.Cite this article: Bone Joint J 2014;96-B:1307–11

Background The direct minimally invasive anterior approach (DMIAA) in total hip arthroplasty (THA) is widely accepted. In our department the DMIAA according to Rachbauer together with the Trident cup and Accolade stem was introduced in 2004. The purpose of the study was to demonstrate the five year results and to analyze the learning curve of a new introduced approach. Patients and Methods Between July 2004 and May 2006 a consecutive series of 151 THA in 147 patients was retrospectively analyzed. All patients were planned to received a THA with the Accolade/Trident implant system using the DMIAA without traction table. Clinical and radiographic data, complications and survivorship were documented with a follow-up of at least 5 years. Results Regarding cup implantation there were 11 (7.3 %) failed intentions to treat due to missing pressfit (8 cases) and acetabular floor perforation (3 cases). No failed intentions to treat occurred during stem implantation. Total implant survival after 5 years follow-up after exclusion of 11 cases with failed intention to treat (n = 140) was 96.9 % (SD 1.4; CI: 94.3 %–99.6 %). After exclusion of the failed intentions to treat (n = 140, n = 4 in the first 20 cases) there was significant (p Discussion THA with Accolade/Trident using the DMIAA without traction table according to Rachbauer temporary exposed patients to a higher risk of implant revisions, which was normalized after the first 20 cases. Results of the learning curve are comparable to other techniques using an orthopaedic traction table. After the typical learning curve, the rate of 5 years implant failure is in accordance with the registry data for non-cemented implants. The Accolade stem showed minimal radiographic signs of radiolucency. Level of evidence IV, retrospective, consecutive case series.

Introduction Cement extrusions on the femoral side after total hip replacement can occur in approximately 0.3% of cemented primary total hip replacements. Not recognised until a postoperative x-ray is performed, the willingness to dismiss and treat these extrusions conservatively is high. Methods We report on 3 patients presenting with sudden onset of thigh pain associated with an inability to weight-bear after a 2 to 15 month period of uneventful healthy recovery from cemented total hip replacement. On immediate postoperative x-rays occult cement extrusion in the posterolateral circumference of the femoral component tip were present. X-rays and CT scans showed no fracture signs. Scintigraphy revealed late increased uptake at the extrusion height. With the hypothesis of imminent femoral fatigue fracture, all patients underwent revision surgery. The defect sites were surgically exposed, thoroughly cleaned of cement, filled with iliac crest bone graft and stabilised with tension band plating. Results This procedure resulted in fully recovered asymptomatic patients at 6 weeks and after a mean follow-up period of 48 months, as demonstrated by their pain level and tolerance of full weight bearing. Conclusions These cases lead us to adopt a low threshold for immediate revision when occult cement extrusion is recognised near the tip of a cemented stem on postoperative films, and to adopt a low threshold for surgical revision when, in the presence of cement extrusion, thigh pain is a complaint. We favour tension band plating and bone grafting over more complex implant revisions since a fast recovery was achieved in these patients.

Femoroacetabular impingement (FAI) has been recognized as a common cause of pain, limited range of motion, and development of early osteoarthritis of the hip in adolescents and adults. Current surgical approaches include femoral osteochondroplasty, acetabular rim resection, and reattachment of torn labrum as either open surgical or arthroscopic techniques as well as periacetabular osteotomy. Conventional radiographs are routinely obtained in the postoperative setting. In addition, MRI serves for work-up in patients with persistent or recurrent groin pain after surgery. Inappropriate correction of the underlying femoral or acetabular osseous abnormality, insufficiency fractures of the femoral neck due to bone resection, intra-articular adhesions, ongoing joint degeneration including advanced cartilage damage, iatrogenic cartilage injury, retear of the labrum, rarely avascular necrosis of the femoral head, defects of the hip joint capsule, or heterotopic ossification might be observed after surgery for FAI.

Background. Procalcitonin (PCT) is a useful surrogate marker for the differentiation of postoperative infection and unspecific inflammatory reaction after surgery. It is known that postoperative course of the PCT serum level varies with type of surgery. No data exists about the postoperative course of serum PCT levels after primary total hip replacement (THR).Purpose. To characterize early postoperative serum PCT levels in uneventful primary THR compared to postoperative levels of different frequently used inflammatory blood parameters.Method. We prospectively investigated 31 patients. Blood samples were taken preoperatively and for 5 days postoperatively. PCT levels were compared with C-reactive protein (CRP), interleukin-6 (IL-6), and blood leucocyte counts (WBC).Results. In uneventful THR PCT levels showed a uniform low-level course with a peak at the second postoperative day. At the fifth day values returned to almost preoperative levels. On contrary, CRP levels remained high during the entire observational period. Only IL-6 levels showed a peak at postoperative day one with a quick and uniform return to preoperative levels.Conclusion. Similar to observations in cardiothoracic, intestinal, and neural surgeries, postoperative course of PCT after primary THR showed a uniform low-level course with a peak at the second postoperative day but below expected levels in systemic infections.

Background:In this study, we investigated the impact of a continuous wound infusion with ropivacaine 0.3% on pain and morphine consumption after minimally invasive hip arthroplasty.Methods:Seventy-six consecutive patients scheduled for elective minimally invasive hip replacement using spinal anesthesia were prospectively included in this double-blind study. Epicapsular placement of a 15-cm fenestrated catheter was performed by the surgeon. Patients were randomized to receive either 20 mL ropivacaine 0.3% (R-group) or 20 mL NaCl 0.9% (P-group) applied into the wound as a bolus before wound closure. A continuous infusion of either ropivacaine 0.3% or placebo was then infused at 8 mL/h for 48 hours after surgery with an elastomeric pump. Morphine IV-patient-controlled analgesia was offered to all patients. Morphine consumption, pain at rest and with motion, and total and unbound ropivacaine plasma concentration were recorded during the 48-hour study period. Postoperative follow-up was performed at 3 months.Results:Demographic and surgical data were similar in both groups. Mean morphine consumption was significantly lower in the R-group than in the P-group during the first 48 postoperative hours: 45.4 ± 9.5 vs 69.7 ± 9.6 (P < 0.0001). There was a mean reduction of 14.4 mg for the first 24 postoperative hours (95% confidence interval [CI] 12.6 to 16.1) and 20.8 mg for the next 24 hours (95% CI 19.1 to 22.4). Pain scores at rest and with motion were lower in the R-group (P < 0.0001). Mean patient satisfaction increased 22.7% from baseline (CI 95% 15.9 to 29.6) in the R-group. Total and unbound ropivacaine plasma concentrations were below toxic levels in the R-group. The free ropivacaine concentration was 0.14 and 0.11 μgmol/L at T(24) and T(48), respectively, in the R-group. At 3 months postoperatively, hip pain and analgesic consumption were similar, but a significant reduction in wound discomfort to touch (31.2; 95% CI 27.7 to 34.7) and pressure (24; 95% CI 20.1 to 27.9) was observed in the R-group (P < 0.0001).Conclusions:Continuous epicapsular wound infusion with ropivacaine 0.3% after minimally invasive hip replacement is an efficient technique for reducing morphine consumption and improving the quality of postoperative analgesia. The beneficial effects of this technique are still present 3 months after surgery.

Introduction: Wondering if the use of drains allowing re-transfusion of shed blood as opposed to closed suction drains or no drains would improve quality of care to patients undergoing simple non-cemented primary total hip replacement (THR) using a direct anterior approach, a three-arm prospective randomized study was conducted. Method: One hundred and twenty patients were prospectively randomized to receive no drain, closed suction drains or drains designed for re-transfusion of shed blood. Blood loss, VAS pain scores, thigh swelling, hematoma formation, number of dressings changed and hospital stay were compared and patients followed for 3months. Results: Drains did not have any significance on postoperative haemoglobin and haematocrit levels or homologous blood transfusion rates. Patients receiving homologous blood transfusions had too small drain volumes to benefit from re-transfusion and patients, who get drained fluid re-transfused, were far away from being in need of homologous blood transfusion. Omitting drains resulted in more thigh swelling accompanied with a tendency of slightly more pain during the first postoperative day but without effect on clinical and radiological outcome at 3months. Earlier dry operation sites resulting in simplified wound care and shorter hospital stay was encountered when no drain was used. Conclusion: The possibility to re-transfuse drained blood was not an argument for using drains and, accepting more thigh swelling, we stop to use drains in simple non-cemented primary THR using the direct anterior approach

Between June 2001 and November 2008 a modified Dunn osteotomy with a surgical hip dislocation was performed in 30 hips in 28 patients with slipped capital femoral epiphysis. Complications and clinical and radiological outcomes after a mean follow-up of 3.8 years (1.0 to 8.5) were documented. Subjective outcome was assessed using the Harris hip score and the Western Ontario and McMaster Universities osteoarthritis index questionnaire. Anatomical or near-anatomical reduction was achieved in all cases. The epiphysis in one hip showed no perfusion intra-operatively and developed avascular necrosis. There was an excellent outcome in 28 hips. Failure of the implants with a need for revision surgery occurred in four hips. Anatomical reduction can be achieved by this technique, with a low risk of avascular necrosis. Cautious follow-up is necessary in order to avoid implant failure.

PURPOSE: The purpose of this study was to evaluate the precision of central hip arthroscopy in the assessment and treatment of pincer-type femoroacetabular impingement (FAI) avoiding the posterolateral portal, with its close proximity to the main arterial blood supply of the femoral head, the medial circumflex femoral artery. METHODS: Seven human cadaveric hips underwent arthroscopic trimming of the acetabular labrum and rim along a preoperatively defined 105 degrees arc of resection for treatment of a presumed pincer-type lesion. After the arthroscopic procedure, all specimens were dissected and measured for evaluation of the location, quantity, and quality of the area undergoing resection. RESULTS: The difference between the actual and planned arc of resection was 18.7 degrees +/- 4.7 degrees (range, 2 degrees to 34 degrees). This was mainly because of a lack of accuracy in the presumed posterior starting point (PSP), with a mean deviation of 19 degrees +/- 3.4 degrees (range, 10 degrees to 36 degrees). Correlation analysis showed that variance in the arc of resection was mainly dependent on the PSP (r = 0.739, P = .058). CONCLUSIONS: Central hip arthroscopy is a feasible option in treating anterosuperior pincer-type FAI by use of the anterior and anterolateral portals only. This cadaveric study showed that there is a significant risk of underestimating the actual arc of resection compared with the planned arc of resection for posterosuperior pincer-type lesions because of the modest accuracy in determining the PSP of the resection. CLINICAL RELEVANCE: Accurate preoperative planning and arthroscopic identification of anatomic landmarks at the acetabular side are crucial for the definition of the appropriate starting and ending points in the treatment of pincer-type FAI. Whereas anterosuperior pincer-type lesions can be addressed very precisely with our technique, the actual resection of posterosuperior lesions averaged 19 degrees less than the planned resection, which may have clinical implications.

To retrospectively evaluate imaging characteristics of surgically proved sublabral recesses and labral tears in the anterior portion of the acetabulum at magnetic resonance (MR) arthrography.Institutional review board approval was obtained; informed consent was waived. The study included 57 patients (36 women [mean age, 37 years], 21 men [mean age, 32 years]) who underwent MR arthrography and either surgery or arthroscopy as reference standard. On MR images, location of sublabral contrast material interposition and depth, shape, and extension into the labral substance of contrast material interpositions were described. Abnormal labral signal intensity (areas of high signal intensity), acetabular cartilage lesions, osseous abnormalities, and perilabral cysts were noted. Mann-Whitney U and Fisher exact tests were performed; interobserver agreement was calculated (kappa statistic and intraclass correlation coefficient).Surgical procedures revealed that 10 (18%) of 57 patients had recesses and 44 (77%) of 57 had tears. Locations of recesses and tears, respectively, were as follows: seven and none, in the 8-o'clock position; two of each, in the 9-o'clock position; one and 22, in the 10-o'clock position; and none and 20, in the 11-o'clock position. None of the recesses extended into the substance of the labrum or through the full thickness of the labral base; 51% (22 of 43) of tears extended into the substance and 49% (21 of 43) of tears extended along the entire labral base. Shape of sublabral contrast material interposition was linear in five (83%) of six recesses and 21 (49%) of 43 tears. Recesses were not associated with abnormal signal intensity of the labrum, cartilage lesions, osseous abnormalities, or perilabral cysts. Of 43 tears, 32 (74%) were associated with abnormal signal of the labrum; 23 (53%), with cartilage damage; 11 (26%), with osseous abnormalities; and eight (19%), with perilabral cysts.Recesses occur as normal variants in the anteroinferior part of the acetabulum. Location in the 8-o'clock position, linear shape of contrast material interposition, partial separation of the labrum, and absence of perilabral abnormalities are characteristics of a recess.

Purpose: To retrospectively assess the frequency and performance of magnetic resonance (MR) arthrography to help diagnose acetabular cartilage delamination in femoroacetabular impingement (FAI). Materials and Methods: Institutional review board approval and informed consent were waived for this retrospective study. Forty-four consecutive patients with FAI of the cam type were included (mean age, 30.7 years; range, 16–49 years), including 30 men (mean age, 30.5 years; range, 16–49 years) and 14 women (mean age, 31.4 years; range, 18–48 years). The inclusion criteria were no previous surgery, surgery within 3 months after MR imaging, and availability of a detailed surgical report with acetabular cartilage findings. MR arthrographic findings were assessed independently by two blinded readers. Findings at surgery served as reference standard. Sensitivity, specificity, accuracy, and κ statistics for interobserver agreement were calculated. Results: At surgery, acetabular cartilage delamination was seen in 23 (...

Introduction: Lequesne's vertical-center-anterior margin (VCA) angle measured on the false profile view of the pelvis aims at quantifying the anterior acetabular coverage of the femoral head. The anterior delimitation of the acetabular roof is often defined on the false profile view but there are no data on its interrater reliability. Additionally, it is not known how pelvic tilt may influence this angle. Finally, the plane in which this angle is measured lies at an angle of 65° to the sagittal plane and we wondered if this angle would be transposable to the anterior acetabular coverage measured in the sagittal plane. Methods: Eight hips from four cadaver pelvises were investigated by means of a total of 72 false profile views, each taken in defined pelvic inclinations at 5° increments ranging from −20° to +20°, and the VCA angle measured by three independent raters. A computed tomography (CT) of each hip was performed in a neutral pelvic tilt position and a sagittal 2D reconstruction calculated in order to measure anterior coverage in the sagittal plane. The interrater reliability of the VCA angles was assessed using the intra-class correlation coefficient (ICC). The dependence of the VCA angle on pelvic tilt was assessed by regression analysis. The Correlation between the VCA angle and anterior coverage in the sagittal plane of the CT was analyzed using a simple linear regression model. Results: The interrater reliability for measurements of the VCA angle was almost perfect (ICC:0.97). Regression analysis showed that each degree of pelvic tilt was accompanied by a change of the VCA angle by a value of 0.63° (P

Purpose: The aim was to clarify the relationship between the posterolateral arthroscopy portal to the hip joint and the deep branch of the medial femoral circumflex artery (MFCA) and its terminal divisions. Methods: In 7 fresh fixated human cadavers, the deep femoral arteries were injected with latex. In all specimens, the standard anterior, anterolateral, and posterolateral arthroscopy portals to the central compartment of the hip were established in a standardized procedure as done in our operating room. Subsequently, all specimens underwent surgical dissection to identify the tract of the posterolateral portal, the course of the deep branch of the MFCA, and its terminal divisions. The distance between the portal tract and the deep branch of the MFCA was measured at its shortest point. Results: None of the specimens revealed injury to the deep branch of the MFCA and its terminal divisions; however, 1 specimen did not reveal filling of the MFCA, and did not allow for accurate measurement. For the remaining 6 specimens, the mean distance of the portal tract to the vessels at the closest point was 10.16 mm (standard deviation, 4.4 mm; range, 5 to 15 mm). In all specimens, the greater trochanter seemed to prevent closer contact between the vessel and the portal tract. Conclusions: As long as the shape of the posterior aspect of the greater trochanter has not been changed by previous surgery, the posterolateral portal to the hip joint can be performed safely with respect to the vital blood supply to the femoral head, because the MFCA is protected by the overhang of the posterior aspect of the greater trochanter, giving a minimum of 3 mm and an average 10 mm of clearance. Clinical Relevance: At the level of the piriformis muscle, the posterolateral portal has a minimum of 3 mm and an average of 10 mm of clearance to the deep branch of the MFCA. As long as the shape of the posterior aspect of the greater trochanter has not been changed, and the skin penetration remains close to this bony margin with direction of the portal toward the joint space, this portal can be performed safely with respect to the vital blood supply to the femoral head.

Introduction Abnormalities in hip morphology can reduce range of motion (ROM) through femoroacetabular impingement (FAI). Structural issues, such as asphericity of the head-neck junction and regional or global acetabular over-coverage, have been extensively discussed in the literature. The effect of varying femoral neck-shaft angle or torsion on native hip range of motion, however, has been poorly studied. Our hypothesis was that varying neck-shaft angles or femoral torsion affect the impingement-free ROM of the hip and can be treated by femoral osteochondroplasty or acetabular rim resection. Material and methods A computer-aided design tool and a 3-D model of the hip were used to simulate incremental deformation of the proximal femur. Neck-shaft angles ranging from 90-160°, and femoral torsions ranging from -15-50°, were created. Femoroacetabular impingement was defined as bone-to-bone contact within physiological hip ROM, as described in the literature. Results and conclusion With decreasing neck-shaft angles (≤110°) or femoral torsion (≤10°), impingement occurred at the anterosuperior rim area. With increasing neck-shaft angles (≥135°) and femoral torsion (≥25°) posteroinferior or ischiofemoral impingement occurred. Acetabular rim trimming could compensate for neck-shaft angles ≥90° and femoral torsion ≥-5°, without creating acetabular dysplasia. Femoral impingement zones in low neck-shaft and low femoral torsion angles were found to be distal to the head-neck junction at the mid-cervical region. The cross-sectional area at this neck region was the smallest, and thus osteochondroplasty at this location may prove potentially dangerous.

Purpose: To determine which MR-arthrography findings are associated with positive hip joint distraction. Materials and methods: One hundred patients with MR arthrography of the hip using axial traction were included. Traction was applied during the MR examination with an 8kg (females) or 10kg (males) water bag, attached to the ankle over a deflection pulley. Fifty patients showing joint space distraction were compared to an age- and gender-matched control group of 50 patients that did not show a joint distraction under axial traction. Two radiologists assessed the neck-shaft angle, lateral and anterior center-edge (CE) angles, CE angles in the transverse plane, extrusion index of the femoral head, acetabular depth, alpha angle, acetabular version, ligamentum teres, joint capsule and ligaments, iliopsoas tendon and the labrum. Results: Mean joint space distraction in the study group was 0.9 ± 0.6mm. Patients with positive joint space distraction had significantly higher neck-shaft angles (control group 131.6 ± 5.4°/study group 134.1 ± 6.1°, p

Highly cross-linked polyethylenes (PE) have been developed with encouraging results in terms of wear. Another body of the literature has indicated potential catastrophic failures related to reduced fatigue properties and oxidation. Each PE available on the market has its own processing characteristics. The aim of this retrospective study was to evaluate the minimum five-year wear properties of an original highly cross-linked PE in a consecutive series of primary THAs. Between August 2005 and December 2007, 80 patients with a mean age of 62.7 years were included. All patients had a 28-mm CoCr femoral head articulating with a highly cross-linked insert (Highcross®, Medacta SA) that was 100 Mrads gamma radiated, remelted at 150 °C, and ethylene oxide sterilized. The primary criterion for evaluation was the femoral head penetration, as measured by Hip Analysis Suite software. The steady state wear was also calculated. Functional results were evaluated according to the WOMAC score. Complete data were available for analysis in 67 patients at a mean follow-up of 5.5 years. The mean femoral head penetration was 0.128 ± 0.62 mm and the steady state wear was−0.025 ± 0.22 mm/year. The WOMAC score significantly decreased from 16.5 ± 5.93 pre-operatively to 4.12 ± 5.5 at the latest follow-up (p

Introduction: Evidence to support or refute closed suction drainage (CSD) in primary total hip replacement (THR) is not conclusive. Our anecdotical experience was that persistent ooze from the drainage hole often delayed wound recovery. We hypothesized that, without CSD, wound care would be simplified without short or long term disadvantage. Materials and methods: Hundred patients scheduled for primary THR were randomly assigned for CSD or non-drainage. Drains were withdrawn at day2. Pain, wound hematoma, number of dressing changes, time of persistent discharge from the operation site (skin incision and drain hole), total blood loss and number of blood transfusions were prospectively recorded. Hip function, presence of heterotopic ossifications (HTO) and complications were recorded at a follow visit 1year after surgery. Results: Wound sites managed without CSD needed significantly less wound dressings (P

To retrospectively characterize magnetic resonance (MR) arthrographic findings in patients with cam femoroacetabular impingement (FAI) and in those with pincer FAI.Institutional review board approval and informed consent were not required. MR arthrographic studies obtained in 50 consecutive patients (30 men, 20 women; mean age, 28.8 years) with FAI were analyzed for labral abnormalities, cartilage lesions, and osseous abnormalities of the acetabular rim. The nonspherical shape of the femoral head at the head-neck junction was measured in eight positions around the femoral head and neck and used to calculate the alpha angle. Acetabular depth was measured. Surgical diagnosis served as the reference standard. The Wilcoxon rank sum test was used for statistical analysis.At surgery, hips in 33 patients were classified as having cam FAI and hips in 17 patients were classified as having pincer FAI. In both groups, the mean age of patients was 28.8 years. There were significantly more men (n = 27) with cam FAI and more women (n = 14) with pincer FAI. The alpha angle was significantly larger in patients with cam FAI at the anterior and anterosuperior positions. The acetabulum was significantly deeper in patients with pincer FAI than in patients with cam FAI. Cartilage lesions at the anterosuperior and superior positions were significantly larger in patients with cam FAI than in patients with pincer FAI. Cartilage lesions at the posteroinferior position were significantly larger and labral lesions at the posterior and posteroinferior positions were more pronounced in patients with pincer FAI than in patients with cam FAI. Osseous abnormalities were not significantly different between the groups. Osseous bump formation at the femoral neck was significantly more common in patients with cam FAI than in patients with pincer FAI.Characteristic MR arthrographic findings of cam FAI include large alpha angles and cartilage lesions at the anterosuperior position and osseous bump formation at the femoral neck; characteristic findings of pincer FAI include a deep acetabulum and posteroinferior cartilage lesions.

The industrially used flame synthesis of silica polymer fillers was extended to amorphous tricalcium phosphate (a-TCP) nanoparticles and resulted in a similar morphology as the traditionally used polymer fillers. Doping of poly(lactide-co-glycolide) (PLGA) with such highly agglomerated a-TCP was investigated for mechanical properties, increased in vitro biodegradation and the formation of a hydroxyapatite layer on the surface of the nanocomposite. PLGA films with particle loadings ranging from 0 to 30 wt% were prepared by solvent casting. Degradation in simulated body fluid (SBF) at 37 °C under sterile conditions for up to 42 days was followed by Raman spectroscopy, scanning electron microscopy (SEM), thermal analysis and tensile tests. The presence of nanoparticles in the PLGA matrix slightly increased the Young's modulus up to 30% compared to pure polymer reference materials. The nanoparticle doped films showed a significantly increased loss of polymer mass during degradation. Scanning electron microscopy images of doped films showed that the SBF degraded the PLGA by corrosion as facilitated by the incorporation of nanoparticulate calcium phosphate. Raman spectroscopy revealed that the deposition of about 10 nm sized hydroxyapatite crystallites on the surface of doped PLGA films was strongly increased by the addition of tricalcium phosphate fillers. The combination of increased hydroxyapatite formation and enhanced polymer degradation may suggest the use of such amorphous, aerosol derived a-TCP fillers for applications in non-load-bearing implant sites.

A malignant lesion extending into the hip may necessitate en bloc resection of the joint, which may result in substantial loss of pelvic bone stock and compromise pelvic stability. Few reports have dealt specifically with the technical aspects of extra-articular resection of the hip1-4. In this report, we present a technique that allows en bloc resection of the hip with use of a periacetabular osteotomy, reconstruction of the acetabulum with an acetabular allograft, and total hip arthroplasty through a combined ilioinguinal and iliofemoral approach. Fig. 1 The utilitarian incision described by Enneking is used. This incision is well suited for a combination of a modified Smith-Petersen approach, representing the standard approach for the Bernese periacetabular osteotomy, and the ilioinguinal approach described by Judet et al., allowing plate application along the anterior column of the pelvis. We present the cases of two patients in whom we performed an extra-articular resection of the hip for the treatment of intra-articular extension of a proximal femoral malignant lesion. By employing the principles of the Bernese periacetabular osteotomy, we preserved the posterior acetabular column and maintained the continuity and stability of the pelvic ring5. Both patients were informed that data concerning the cases would be submitted for publication. Fig. 2 En bloc resection of the hip was performed with use of a periacetabular osteotomy, as described by Ganz et al., leaving the posterior column intact. The osteotomies were performed in the following order: ischial (a), pubic (b), anterior aspect of the ilium (c), and posterior aspect of the ilium (d). Fig. 3 An acetabular allograft (hatched area) is used for reconstruction of the acetabular bone stock. The graft is fixed with screws (not shown in the diagram but can be seen in Figures 4-B and 5-C) augmented with an anterior reconstruction plate. Fig. 4-A Figs. 4-A and …

Osteoarthritis of the hip is one of the major causes of pain and disability in the developed world. Resulting therapeutic interventions and socioeconomic expenditures pose a considerable burden on health and social services. Based on experimental and clinical studies, including in situ inspection in consecutive adolescents and young adults undergoing surgical dislocations of the hip, we propose femoroacetabular impingement to cause early osteoarthritis in the nondysplastic hip; morphologic deviations of the acetabulum (regional or global overcoverage) and/or proximal femur with a decreased anterior head-neck offset may lead to repetitive trauma of the peripheral articular cartilage during flexion and internal rotation, particularly in individuals taking regular exercises. Frequently, this becomes symptomatic in the second and third decade of life in patients with an increased sportive activity. Based on predominance of the acetabular or femoral pathology, 2 different types of FAI, the pincer and the cam, are differentiated. Apart from these morphological alterations, a supraphysiological mobility and overuse can contribute to the FAI. The impingement concept has led to a new type of mainly intracapsular hip surgery aimed at improving clearance of the hip to avoid pathological contact.

To prospectively evaluate magnetic resonance (MR) imaging findings of abductor tendons and muscles in asymptomatic and symptomatic patients after lateral transgluteal total hip arthroplasty (THA).The institutional review board approved the study, and all patients provided informed consent. Two musculoskeletal radiologists blinded to clinical information analyzed triplanar MR images of the greater trochanter obtained in 25 patients without and 39 patients with trochanteric pain and abductor weakness after THA. Tendon defects, diameter, signal intensity, and ossification; fatty atrophy; and bursal fluid collections were assessed. In 14 symptomatic patients, MR imaging and surgical findings were correlated. Differences in the frequencies of findings between the two groups were tested for significance by using chi2 analysis.Tendon defects were uncommon in asymptomatic patients and significantly more frequent in symptomatic patients: Two asymptomatic versus 22 symptomatic patients had gluteus minimus defects (P.001); four asymptomatic versus 24 symptomatic patients, lateral gluteus medius defects (P.001); and no asymptomatic versus seven symptomatic patients, posterior gluteus medius defects (P = .025). In both patient groups, tendon signal intensity changes were frequent, with the exception of those in the posterior gluteus medius tendon, which demonstrated these changes more frequently in symptomatic patients (in 23 vs five asymptomatic patients, P = .002). Tendon diameter changes were frequent in both groups but significantly (P = .001 to P = .009) more frequent in symptomatic patients (all tendon parts). Fatty atrophy was evident in the anterior two-thirds of the gluteus minimus muscle in both groups, without significant differences. In the posterosuperior third of the gluteus minimus muscle, however, differences in fatty atrophy between the two groups were significant (P = .026). Fatty atrophy of the gluteus medius muscle was present in symptomatic patients only, with significant differences among all muscle parts. Bursal fluid collections were more frequent in symptomatic patients (n = 24) than in asymptomatic patients (n = 8, P = .021). The MR imaging-based diagnosis was confirmed in all 14 patients who underwent revision surgery.Abductor tendon defects and fatty atrophy of the gluteus medius muscle and the posterior part of the gluteus minimus muscle are uncommon in asymptomatic patients after THA.

To retrospectively evaluate if the degree of disk degeneration and disk herniation volume at magnetic resonance (MR) imaging are risk factors for recurrent disk herniation.The institutional review board permits such retrospective studies, and individual informed consent was not required. MR imaging findings obtained before initial diskectomy in 30 patients (mean age, 42.8 years; 10 women, 20 men) with recurrent disk herniation (study group) and 30 patients (mean age, 42.2 years; nine women, 21 men) without recurrence for at least 2 years after surgery (control group) were compared. Disk degeneration was assessed on T2-weighted sagittal MR images with a five-point grading system (grade I indicated no degeneration; grade II, horizontal hypointense bands within disk; grade III, inhomogeneous disk with intermediate signal intensity; grade IV, no distinction between inner and outer parts of disk; and grade V, collapsed hypointense disk). Disk herniation was classified as representing protrusion, extrusion, or sequestration. The volume of both the affected intervertebral disk and the herniated disk material was measured. Qualitative and quantitative analyses were performed by two readers. The chi(2) test was used for comparison of categorical variables. For comparison of disk degeneration and volumes between patients with and those without recurrence, a paired two-tailed t test was used. Odds ratios based on the extent of disk degeneration were calculated for the entire sample.Advanced disk degeneration (grades IV and V) was significantly less frequent in the study group than in the control group (P.006). The risk of recurrent disk herniation decreased by a factor of 3.4 for each increase in grade of disk degeneration (odds ratio: 3.58; 95% confidence interval: 1.3, 9.6; P = .011). Mean disk herniation volume as a percentage of intervertebral disk volume was 10.59% +/- 3.41 in the study group and 11.56% +/- 3.84 in the control group. This difference was not significant (P = .31).Minor disk degeneration but not herniation volume represents a risk factor for the recurrence of disk herniation after diskectomy.

The objective of our study was to compare the diagnostic performance of a dedicated cartilage MR sequence (water-excitation 3D double-echo steady-state) with a standard MR sequence (T1-weighted spin-echo) in detecting articular cartilage lesions of the hip after intraarticular injection of gadopentetate dimeglumine.In 50 MR arthrograms of the hip joint obtained in 47 consecutive patients, a sagittal 3D double-echo steady-state sequence (TR/TE, 24/6.5; flip angle, 25 degrees ) was compared with a sagittal T1-weighted spin-echo sequence (350/14). Two musculoskeletal radiologists independently evaluated articular cartilage. Sensitivity and specificity for detecting cartilage defects were calculated for those hips that underwent open surgery (n = 21). Lesion conspicuity was retrospectively reviewed and graded between 1 (not visible) and 5 (well defined).At surgery, a total of 26 lesions of the acetabular (n = 20) and femoral (n = 6) cartilage were found. For the 3D double-echo steady-state and T1-weighted spin-echo sequences, sensitivities and specificities for cartilage lesion detection were 58% and 88% and 81% and 81% for reviewer 1 and 62% and 94% and 62% and 100% for reviewer 2, respectively. Lesion conspicuity was significantly superior (p = 0.036) for the 3D double-echo steady-state sequence (mean grade, 3.4) compared with the T1-weighted spin-echo sequence (mean grade, 3.0). The kappa value was fair for the 3D double-echo steady-state sequence (kappa = 0.40) and moderate for the T1-weighted spin-echo sequence (kappa = 0.55).The 3D double-echo steady-state sequence optimized for cartilage imaging improves lesion conspicuity but does not improve diagnostic performance.

A retrospective radiographic analysis of the acetabulum of 13 patients (14 hips) with proximal femoral focal deficiency (PFFD), clinically classified into Gillespie and Torode type 1, was performed to better understand its morphologic features at maturity. The version of the proximal part of the acetabulum was determined quantitatively and qualitatively. All 14 hips showed residual or borderline acetabular dysplasia with a mean lateral centre-edge angle of -1.5degrees and an acetabular index of 30degrees. The acetabular dome was retroverted in all hips and averaged -24degrees. Acetabular deficiency compared with the opposite side, while not present with respect to the anterior wall, averaged 12% with respect to the posterior wall. Dysplasia associated with type 1 PFFD is therefore fundamentally different from that seen in developmental residual hip dysplasia. Clinically, despite radiographic evidence of dysplasia, 57% were without clinical manifestations of hip pathology. This may be due to a number of factors including age of last radiograph, severity of dysplasia, and the decreased functional demand placed on the hip in some individuals with associated malformations. For the symptomatic hip, the posterior insufficiency and relative retroversion of the acetabular dome should be taken into consideration in planning reorientation procedures. This can help to prevent problems of persistent subluxation or acetabulo-femoral impingement following reconstruction.

Spinal canal dimensions are assumed to play a significant role with regard to the development of symptoms in individuals with disc herniations. The literature is inconclusive on the significance of spinal canal size as a risk factor for sciatica, mainly because of study design problems. The objective of this study, therefore, was to test the hypothesis that spinal canal dimensions are a significant risk factor for the development of sciatica, comparing symptomatic and asymptomatic individuals. Thirty symptomatic patients undergoing lumbar discectomy and 45 asymptomatic volunteers were investigated by clinical and MRI examination. The size of the spinal canal and thecal sac as well as the midsagittal spinal canal diameter were measured using a point counting method and scanner software, respectively. Differences between the groups were compared separately for each level L3/4 to L5/S1. The intra- and inter-observer error ranged between 0.95 and 0.99 for all measurements. In symptomatic patients, the dimensions of the spinal canal and thecal sac as well as the midsagittal spinal canal diameter were smaller at all disc levels. Unpaired t-test demonstrated a significant difference, ranging from P