Patients risk for mortality at 90 days after proximal femur fracture - a retrospective study in a tertiary care hospital.

BACKGROUND: Despite improving the management of proximal femur fractures (PFF) with legal requirements of timing the surgery within 24 h, mortality rates in these patients remain still high. The objective of our study was to analyze potential cofactors which might influence the mortality rate within 90 days after surgery in PFF to avoid adverse events, loss of quality of life and high rates of mortality. METHODS: In this retrospective, single-center study all patients with PFF aged 65 years and older were included. We recorded gender, age, type of fracture, surgery and anesthesia, time, comorbidities and medication as well as complications and mortality rate at 90 days. Separate logistic regression models were used to assess which parameters were associated with patients' mortality. The mortality rate was neither associated with timing, time and type of surgery nor time and type of anesthesia, but with higher age (OR 1.08 per year; 95% CI 1.034-1.128), lower BMI (OR 0.915 per kg/m2; 95% CI 0.857-0.978), higher CCI (OR 1.170 per point; 95% CI 1.018-1.345), dementia (OR 2.805; 95% CI 1.616-4.869), non-surgical complications (OR 2.276; 95% CI 1.269-4.083) and if mobilization was impossible (OR 10.493; 95% CI 3.612-30.479). RESULTS: We analyzed a total of 734 patients (age ≥ 65 years) who had a PFF in 2019 and 2020 and received surgery. 129 patients (17.6%) died until 90 days at an median age of 89.7 years (range 65-101 years). CONCLUSION: The proportion of patients who died until 90 days after surgery is still high. It is less extend influenced by surgical and anaesthesiologic factors than by patient-related factors like age or lower BMI. Physicians should be aware of the importance of avoiding adverse events and the importance of patients' mobilization to reduce mortality and improve patients' outcome.

Girdlestone resection arthroplasty for femoral neck fractures has poorer outcomes than hemiarthroplasty in frail patients with increased risk for arthroplasty-related complications: a retrospective case study of 21 patients.

BACKGROUND AND PURPOSE: Hemiarthroplasty (HA) is the usual treatment for displaced femoral neck fractures (FNF) in elderly patients. Patients may be unsuitable for HA due to secondary conditions such as systemic infections or severe neurological conditions, which is why Girdlestone resection arthroplasty (GRA) may be an option. We aimed to determine (1) patient survival in matched patient groups treated with either GRA or HA and (2) functional outcomes. PATIENTS AND METHODS: 21 patients treated with GRA for FNF in a German university hospital were retrospectively reviewed (2015-2019). After matching for age and comorbidities, a control group of 42 HA patients was established. Patient survival was determined by a Kaplan-Meier analysis. The mean follow-up (FU) was 1.5 (0-4.4) years. Function at FU was documented using the modified Harris Hip Score (mHHS) and the National Hip Fracture Database (NHFD) mobility score. RESULTS: The 1-month-mortality was 19% in the GRA group and 12% in the HA group; the 1-year mortality was 71% and 49%, respectively (P = 0.01). The mHHS at FU was lower in the GRA group than in the HA group (22 [range 0-50] vs. 46 [11-80]). 82% of patients in the GRA group were bedridden post-surgery as opposed to 19% in the HA group. CONCLUSION: Patients with HA after FNF had higher survival and better functional outcomes when compared with GRA in matched patient groups. Considering this, GRA for FNF should be selected restrictively.

Treatment of Severe Acetabular Defects With an Antiprotrusio Cage and Trabecular Metal Augments - Clinical and Radiographic Results After a Mean Follow-Up of 6.6 Years.

BACKGROUND: Large acetabular bone defects present a serious challenge in revision total hip arthroplasty. The off-label use of antiprotrusio cages in combination with tantalum augments is a promising treatment option in these difficult situations. METHODS: Between 2008 and 2013, 100 consecutive patients underwent acetabular cup revision with a cage-augment combination in Paprosky 2 and 3 defect types (including pelvic discontinuities). There were 59 patients available for follow-up. The primary endpoint was the explantation of the cage-and-augment construct. The secondary endpoint was acetabular cup revision for any reason. Also, radiographic and functional outcomes (Western Ontario and McMaster Universities Osteoarthritis Index, Harris Hip Score) were evaluated. Implant survival rates were determined using a Kaplan-Meier analysis. The significance level was set at P < .05. RESULTS: Explantation-free survivorship of the "Cage-and-Augment" system was 91.9% after a mean follow-up of 6.2 years (range, 0 to 12.8). All 6 explantations were due to periprosthetic joint infection (PJI). The overall revision-free implant survival rate was 85.7%, including 6 additional liner revisions due to instability. In addition, 6 early PJI occurred, which were successfully treated with debridement, irrigation, and implant retention. We did observe one patient who had radiographic loosening of the construct without necessity for treatment. CONCLUSION: The combination of an antiprotrusio cage with tantalum augments is a promising technique in treating large acetabular defects. A major risk of PJI and instability due to large bone and soft tissue defects needs special attention.

Cementation of a dual mobility cup in a well-fixed acetabular component- a reliable option in revision total hip arthroplasty?

BACKGROUND: The "cup-in-cup" technique allows for revision of failed total hip arthroplasty (THA) when the cementless cup is well fixed. Furthermore, it can be used for liner wear or mechanical failure where liner replacement may be impossible or impractical. Recently, the "cup-in-cup" technique in combination with dual mobility cups (DMC) has drawn increased attention. Our aim was to report on the clinical and radiographic outcomes following this surgery. METHODS: From 2015 to 2020, 33 patients treated with the DMC- "cup in cup" technique were retrospectively reviewed. Fourteen patients had died while 19 were available for the final follow-up (FU), of which 15 underwent both a radiograph and a FU visit, 2 underwent a radiograph only and 2 underwent a telephone interview only. Patient-related outcome measures included the HHS and the WOMAC. Radiographs were assessed for implant loosening and positioning. Primary endpoint was revision of any cause and secondary endpoint was loosening of the DMC at the latest FU. The survival analysis was conducted using the Kaplan-Meier method. RESULTS: The mean age at surgery was 78.6 ± 7.1 (63-93) years and the mean surgery duration was 124.4 ± 52.0 (60-245) minutes. Recurrent dislocation (42.4%), periprosthetic fracture (39.4%) and polyethylene wear (6.1%) were the most frequent reasons for surgery. The mean FU duration (n = 19) was 28.5 ± 17.3 (3-64) months. The mean HHS score at FU was 59.4 ± 22.2 (29-91) and the mean WOMAC score was 59.7 ± 25.6 (15.6-93.8). Two cups were revised due to instability and one revision was performed due to periprosthetic joint infection, accounting for an overall cup survival rate of 86.8% after a mean FU of 22.9 ± 18.0 (1.5-64.6) months. The survival rate free of loosening was 90.9% after a mean FU of 22.3 ± 18.5 (1.5-64.7) months. CONCLUSIONS: We found that the cementation of a DMC in a well-fixed cup is a promising short- to mid-term treatment addressing THA instability especially in elderly and frail patients, who benefit from a reduced operation time. Proper cementation technique, adequate cup positioning as well as selection of a sufficiently large DMC are crucial for treatment success. Longer FUs will be needed in the future in order to further prove the benefit of this technique.

[Femoral neck stress fractures and femoroacetabular impingement : A retrospective case study and literature review]. / Stressfrakturen des Schenkelhalses bei femoroazetabulärem Impingement : Eine retrospektive Fallstudie und Literaturübersicht.

BACKGROUND: Femoroacetabular impingement (FAI) can lead to morphologic damage of both the acetabulum and the femoral neck. Recent reports have found an association between impingement deformities and the development of femoral neck stress fractures. The aim of this study was to report a series of patients with these findings and to update the current evidence on the topic. MATERIAL AND METHODS: 5 patients (6 cases) with atraumatic femoral neck fractures and FAI were identified in the Dresden hip registry from 2015 to 2018. Demographic data, comorbidities, radiographic results and bone metabolism results were described. A literature search was conducted using keywords related to femoral neck stress fractures and FAI syndrome. RESULTS: The average age of the series was 39 (range: 22-52), 2 patients were female and 3 male. A total of 12 surgical procedures were performed. 4 of the 5 patients showed radiographic features of pincer and/or cam-FAI, whereas 3 patients had a decreased femoral antetorsion (-7° to +7° antetorsion). In 3 patients, magnetic resonance imaging revealed additional signs of avascular necrosis ARCO I. There was a lack of FAI-specific treatment recommendations in the available literature. DISCUSSION: Radiographic results of the patients evaluated suggested that impingement-associated deformities of the hip may cause femoral neck stress fractures, which is in line with the available literature. This potential coincidence should be integrated in diagnostic algorithms and therapeutic approaches.

MRI-based static and functional assessment of complex hip deformities in comparison with CT: a validation study.

OBJECTIVE: This study aimed at investigating the agreement between predefined quantitative parameters of hip morphology derived from magnetic resonance imaging (MRI) and virtual range of motion (ROM) analysis using computed tomography (CT) as standard of reference. METHODS: Twenty patients (13 females, 7 males, 16-59 years) with hip deformities underwent MRI prior to surgery. Clockwise alpha angle, femoral head and neck diameter, collum caput diaphysis angle, femoral torsion, center-edge angles, acetabular coverage of the femoral head, sourcil angle, and acetabular anteversion were measured. Additionally, tern single and combined movements were simulated using a motion analysis program. The MRI findings were compared with the corresponding results obtained by CT. Correlation of MRI with CT was assessed using different statistical methods (intraclass correlation coefficient, Bland-Altmann plot, two one-sided t test), and linear regression analysis was performed. RESULTS: The results showed near-perfect intraclass correlation coefficients (ICCs) for anteversion (0.95), acetabular sector angles (0.98-0.99), sourcil angle (0.95), and acetabular coverage (anterior 0.96, posterior 0.99). Intermethod correlation for femoral parameters showed almost perfect agreement except for the alpha angle (0.73-0.97). No significant proportional bias was detected for traditional acetabular and femoral parameters. ROM analysis was performed for 370 movements in 37 hips. For 78.4% (290/370) of the movements analysed, neither CT nor MRI detected impingement across the physiological ROM. For 18.6% (69/370) of the movements, impingement was detected by both CT and MRI, while 2.2% (8/370) of the movements with impingement in CT showed no impingement in MRI, and 0.8% (3/370) of the movements with impingement in MRI had no corresponding result in CT. CONCLUSION: Finally, it was concluded that MRI-based assessment of hip morphology and virtual ROM analysis is feasible and can be performed with good intermethod agreement in comparison to the gold standard (CT). Therefore, MRI appears to be substantially equivalent to CT for use in virtual ROM analysis and so may reasonably be used in place of CT for this purpose.

Acetabular- and femoral orientation after periacetabular osteotomy as a predictor for outcome and osteoarthritis.

BACKGROUND: Periacetabular osteotomy is a successful treatment for hip dysplasia. The results are influenced, however, by optimal positioning of the acetabular fragment, femoral head morphology and maybe even femoral version as well as combined anteversion have an impact. In order to obtain better insight on fragment placement, postoperative acetabular orientation and femoral morphology were evaluated in a midterm follow-up in regard to functional outcome and osteoarthritis progression. METHODS: A follow-up examination with 49 prospectively documented patients (66 hips) after periacetabular osteotomy (PAO) was performed after 62.2 ± 18.6 months. Mean age of patients undergoing surgery was 26.7 ± 9.6 years, 40 (82%) of these patients were female. All patients were evaluated with an a.p. pelvic x-ray and an isotropic MRI in order to assess acetabular version, femoral head cover, alpha angle, femoral torsion and combined anteversion. The acetabular version was measured at the femoral head center as well as 0.5 cm below and 0.5 and 1 cm above the femoral head center and in addition seven modified acetabular sector angles were determined. Femoral torsion was assessed in an oblique view of the femoral neck. The combined acetabular and femoral version was calculated as well. To evaluate the clinical outcome the pre- and postoperative WOMAC score as well as postoperative Oxford Hip Score and Global Treatment Outcome were analyzed. RESULTS: After PAO acetabular version at the femoral head center (31.4 ± 9.6°) was increased, the anterior cover at the 15 o'clock position (34.7 ± 15.4°) was reduced and both correlated significantly with progression of osteoarthritis, although not with the functional outcome. Combined acetabular and femoral torsion had no influence on the progression of osteoarthritis or outcome scores. CONCLUSION: Long-term results after PAO are dependent on good positioning of the acetabular fragment in all 3 planes. Next to a good lateral coverage a balanced horizontal alignment without iatrogenic pincer impingement due to acetabular retroversion, or insufficient coverage of the anterior femoral head is important.

Which disease-related factors influence patients' and physicians' willingness to consider joint replacement in hip and knee OA? Results of a questionnaire survey linked to claims data.

BACKGROUND: A great heterogeneity in total joint replacement (TJR) rates has been reported for osteoarthritis (OA), most likely arising from a gap between patients' and physicians' views on the need for TJR. The purpose of this study therefore was to analyze potential cofactors which might influence the desire of patients to undergo TJR and physicians' willingness to discuss surgery with their patients. METHODS: A total of 8995 patients in Germany with a claims data diagnosis of hip or knee OA or polyarthrosis were asked to complete a questionnaire for this cross-sectional study of sociodemographic factors, indicators of current joint function (WOMAC score), willingness to undergo TJR and whether they had already discussed TJR with a physician. The overall response rate was 40%. Responders with polyarthrosis and individuals without current or chronic symptoms in the corresponding joints, pain in already replaced joints or simultaneous symptomatic hip and knee OA were excluded. We linked the survey results to claims data. Separate logistic regression models were used to assess which parameters were associated with patients' willingness to undergo TJR and physicians' discussion of surgery. RESULTS: We analyzed 478 hip OA and 932 knee OA patients. Just 17% with hip OA and 14% with knee OA were willing to undergo TJR, although 44 and 45% had already discussed surgery with their physicians. Patients' willingness was associated with higher WOMAC scores, a deterioration of symptoms over the last 2 years, and previous TJR for another joint. The discussion with a physician was influenced by the impact on personal life and previous arthroplasty. Older age (odds Ratio (OR) 1.2 per 10 years), male sex (OR 0.69 vs female), longer symptom duration (OR 1.08 per 5 years), deterioration of symptoms (OR 2.0 vs no change/improvement), a higher WOMAC score (OR 1.3 per 10% deterioration) and reduced well-being (OR 1.1 per 10% deterioration) were associated with physician discussion in knee OA patients. CONCLUSIONS: The proportion of patients willing to undergo TJR is lower than the proportion in whom physicians discuss surgery. While previous TJR seems to enhance patients' and surgeons' willingness, the influence of other cofactors is heterogeneous.

[Frequencies of musculoskeletal symptoms and disorders in the population-based German National Cohort (GNC)]. / Häufigkeiten muskuloskelettaler Symptome und Erkrankungen in der bevölkerungsbezogenen NAKO Gesundheitsstudie.

BACKGROUND: Musculoskeletal diseases and symptoms are very common in the general population. They lead to high healthcare costs and pose a significant burden to the national economy. OBJECTIVES: Based on data from the population-based German National Cohort (GNC), frequencies of musculoskeletal symptoms and diseases are reported, including back pain, osteoporosis, osteoarthritis, and arthritis. MATERIALS AND METHODS: Data were collected from March 2014 to March 2017 in adults aged 20-75 years during the first half of the baseline survey of the GNC. The sample comprised 101,779 interviewed subjects, including 9370 subjects who underwent clinical musculoskeletal examinations. The interview included questions about specific musculoskeletal disorders. A clinical examination of the hand provided information about palpable swollen joints and pressure-sensitive joints. Resting pain of the knees and hips was also assessed by a clinical examination. Frequencies were standardized to the German standard population of the year 2011. RESULTS: Having ever been diagnosed with recurrent back pain (22.5%) or osteoarthritis (20.6%) were the most common complaints reported in the interview; osteoporosis (2.9%) and rheumatoid arthritis (1.9%) were stated more seldom. According to the hand examination, 6.0% of all participants experienced pain in at least one finger joint. Resting pain was present in at least one knee among 8.2% and in at least one hip among 5.1% of the participants as assessed during the clinical examination. Women were more likely to report musculoskeletal disorders and symptoms than men. The proportion of adults affected by musculoskeletal diseases increased strongly with age. CONCLUSION: Musculoskeletal disorders and symptoms occur frequently. The burden of complaints and diagnoses is comparable to previous population-based surveys.

Is MRI an adequate replacement for CT scans in the three-dimensional assessment of acetabular morphology?

BACKGROUND: Appropriate three-dimensional imaging of the hip joint is a substantial prerequisite for planning and performing surgical correction of deformities. Although surgeons still use computed tomography (CT), modern and fast acquisition techniques of volumetric imaging using magnetic resonance imaging (MRI) for pelvic measurements enable similar resolution. PURPOSE: This study was designed to determine if already described measures of acetabular morphology are comparable in both techniques and if assessment can be performed with equal intra-observer and inter-observer reliability. MATERIAL AND METHODS: Thirty-two hips (16 patients) were examined with a pelvic CT and a MRI with 3-T. Pelvic orientation was standardized by each observer in coronal, axial, and sagittal planes. Acetabular version as well as seven acetabular sector angles were measured by two observers twice with a minimum of four weeks between sessions. RESULTS: Inter-rater reliability showed excellent results for intra- and inter-rater reliability for CT (0.977-0.999) and MRI (0.969-0.998) measuring acetabular version and sector angles. Evaluating the reliability of CT and MRI for each observer revealed excellent results (0.972-0.998). Evaluating the Bland-Altman plots for intra-observer reliability showed an equal distribution of angles, within acceptable 95% limits of agreement. The same results were observed for inter-observer reliability evaluating CT and MRI as well as inter-method reliability. CONCLUSION: Modern MRI scans are equally applicable to assess the bony pelvis as CT scans. In addition, MRI would enable the examination of soft tissues such as chondrolabral structures and muscle in the same examination. Since hip-preserving surgery is mostly conducted in younger patients, the reduction of radiation exposure is a benefit.

[Utilization of individual out-of-pocket health services (IGeL) in persons with osteoarthritis in Germany : Results of a survey from the PROCLAIR study]. / Inanspruchnahme von individuellen Gesundheitsleistungen (IGeL) bei Arthrose in Deutschland : Ergebnisse einer Befragung im Rahmen der PROCLAIR-Studie.

BACKGROUND: Little is known about the utilization of individual health services performed by a physician (IGeL) and the services and supplements provided outside a doctor's office (MuPaP) for osteoarthritis patients. OBJECTIVES: The aims of this study are to analyze the use of osteoarthritis-specific IGeL and MuPaP as well as predictors for their utilization. MATERIALS AND METHODS: For this cross-sectional study, claims data was used to identify all persons with hip, knee, or polyarticular osteoarthritis in 2014 (n = 657,807). A random sample (n = 8995) was sent a questionnaire about their usage of IGeL and MuPaP. Furthermore, the type of physicians conducting or recommending services was evaluated. Applying multivariable logistic regression, predictors associated with the utilization of IGeL, MuPaP, and overall individual health services were analyzed. RESULTS: After validating the data and osteoarthritis diagnosis, 2363 persons were enrolled (mean age: 65.5 years, 72% female). In the last 12 months, 39% of patients had used at least one IGeL (MuPaP: 76%), with 86% being primarily performed by orthopedists (MuPaP: 88% patient self-motivated). Knee osteoarthritis was associated with increased utilization of IGeL. Having female gender, higher income, residence in Western Germany, higher disease burden, and lower satisfaction with the healthcare system were influences on the use of overall individual health services. CONCLUSIONS: Since patients with high disease burden in particular tend to use these therapies with varying treatment success, detailed information, especially about the risks and existing evidence, should be a prerequisite for trustworthy doctor-patient relationships.

[Prescription frequency of physical therapy and analgesics before total hip and knee arthroplasy : An epidemiological analysis of routine health care data from Germany]. / Verordnungshäufigkeit physikalischer Therapien und Analgetika vor dem Einsatz einer Hüft- bzw. Kniegelenks-Endoprothese : Eine versorgungsepidemiologische Analyse basierend auf GKV-Routinedaten aus Deutschland.

BACKGROUND: Osteoarthritis of the hip or knee joint is a widespread disease with a strong influence on the quality of life. At present, the extent of conservative treatment with physical therapies and analgesics before the use of a total joint arthroplasty (TJA) of the hip or knee is largely unclear in Germany. OBJECTIVES: The aim was to analyze the prescription frequency according to regional and socio-demographic factors. MATERIALS AND METHODS: Based on routine health care data from BARMER insurance, patients who received a TJA of the hip or knee from 2011 to 2013 were analyzed. Included were consistently insured patients with the main discharge diagnosis of osteoarthritis who did not receive any further TJA for eight quarters before and after replacement. The prescription frequency of physical therapies and analgesics, stratified according to age groups, gender, number of comorbidities and federal state was analyzed. RESULTS: 40,242 persons with hip TJA and 35,652 persons with knee TJA were included. In the year prior to surgery, 49.4% of patients (hip TJA: 49.9%; knee TJA: 48.9%) received at least one physical therapy and 81.0% were prescribed analgesics. Regionally, the prescription frequency of physical therapies for hip TJA varied between 35.7% (Bremen) and 70.6% (Saxony) and for knee TJA between 37.6% (Saarland) and 66.9% (Saxony). CONCLUSION: The prescription frequency of physical therapy does not fully correspond to current treatment recommendations. The prescription of physical therapies in the year before the TEP shows regional differences, with fundamentally lower prescription frequencies in the former states of West Germany.

What Are the Results of Surgical Treatment of Hip Dysplasia With Concomitant Cam Deformity?

BACKGROUND: Periacetabular osteotomy (PAO) is a reliable procedure to correct the deficient acetabular coverage in hips with developmental dysplasia. It is unclear how the presence of additional femoral cam-type deformity might influence the clinical and radiographic treatment results of PAO. QUESTIONS/PURPOSES: (1) Are there differences in clinical scores (WOMAC, EQ-5D) and examination findings (impingement sign) or radiographic measures of acetabular orientation and head sphericity after PAO for isolated acetabular dysplasia when compared with the combined pathology of dysplasia and additional femoral cam deformity? (2) Are these clinical and radiographic findings after combined surgical therapy for additional cam deformity influenced by different pathology-adjusted surgical techniques? METHODS: From July 2005 to December 2010, 86 patients (106 hips) underwent PAO for hip dysplasia. Surgical and outcome data were prospectively collected and retrospectively reviewed in a comparative observational study. Indications for surgery were a lateral center-edge angle less than 25° and hip pain for at least 6 months. The contraindications for surgery were advanced radiographic osteoarthritis (Kellgren-Lawrence Grade 3), incongruency of joint space, and patient age > 50 years. Depending on preoperative hip ROM, impingement test, and presence of a radiographically visible cam deformity, treatment allocation was performed: Group I: isolated PAO in patients without symptomatic asphericity, Group IIa: PAO with subsequent osteochondroplasty through arthrotomy for patients with symptomatic cam deformity and no labrochondral pathology, and Group IIb: arthroscopically assisted osteochondroplasty and additional labrochondral repair with subsequent PAO when patients had labrochondral lesions in addition to a symptomatic cam deformity. Clinical outcome (impingement test, EQ-5D, WOMAC) as well as radiographic parameters (lateral center-edge angle, crossover sign, alpha angle, osteoarthritis grade) were obtained after a mean followup of 63 ± 18 months (range, 31-102 months) and compared with the baseline data. Eleven patients (13%) were lost to followup. With the numbers available, our study had 80% power to detect a difference between Groups I and II of 10 points on the WOMAC scores. RESULTS: There was no difference in the increase of WOMAC scores in patients with PAO alone (Group I; preoperative score 74 ± 17 versus postoperative 91 ± 15, p = 0.033) when compared with PAO and concurrent osteochondroplasty (Groups II A and B preoperative 73 ± 19 versus postoperative 90 ± 13 p < 0.001). The mean postoperative alpha angles in Group II (38° ± 6°) improved when compared with preoperative values (56° ± 15°; p < 0.001) and were even lower than native offset alpha angles in Group I (47° ± 11°). Clinical scores as well as postoperative radiographic parameters were not different between patients with conventional osteochondroplasty alone (Group IIA) and patients with arthroscopically assisted cam resection and intraarticular labrochondral repair (Group IIB). CONCLUSIONS: With the numbers available, we detected no differences in outcome scores and radiographic results between patients who had been treated with PAO alone and patients who underwent combined PAO and offset correction for cam deformity. Although arthroscopically assisted treatment of advanced labrochondral lesions together with osteochondroplasty is possible during PAO and the results were not different in this small study when compared with patients with PAO and osteochondroplasty alone, the type and extent of damage that would indicate additional cartilage surgery over cam resection alone remain unclear. LEVEL OF EVIDENCE: Level III, therapeutic study.

The First SICOT Oral Presentation Award 2011: imageless computer-assisted femoral component positioning in hip resurfacing: a prospective randomised trial.

PURPOSE: The aim of the study was to evaluate the effects of imageless computer-assisted surgery (CAS) on the accuracy of positioning of the femoral component and on the short-term clinical outcome in hip resurfacing (HR) using a randomised prospective design. METHODS: A total of 75 consecutive patients undergoing HR were randomly allocated to CAS and conventional implantation, respectively. Preoperatively and six months post-operatively standardised pelvic anteroposterior X-ray images, the total Western Ontario and McMaster Universities Osteoarthritis Index, the Harris Hip Score and the EQ-5D utility index were evaluated in a blinded manner. The primary end point of the study was a post-operative femoral component malpositioning in five degrees or more either varus or valgus absolute deviation from the planned stem shaft angle. RESULTS: Patient demographics and algofunctional scores did not differ between the CAS and conventional implantation samples. Using CAS fewer femoral components were positioned in five or more degrees absolute deviation (4/37 vs 12/38, Fisher's exact p = 0.047; 95 % confidence interval for the primary end point's incidence difference: +3 %; +39 %); the respective incidences of five or more degrees of varus deviation were 0/37 vs 5/38. One conversion to a stemmed prosthesis (CAS group) was performed for periprosthetic femoral neck fracture. Radiological signs of superolateral femoral neck/implant impingement were observed in two cases (one CAS-based and one conventional implantation). CONCLUSIONS: The accuracy of femoral HR component positioning was significantly improved using CAS. However, one major complication necessitated early revision in the CAS group at six months of observation. Apart from that adverse event no inter-group differences were observed for the short-term clinical outcome. Future studies need to address the clinical long-term relevance of CAS in HR.

[Hip dysplasia: What influence do age, arthrosis and concomitant diseases have on the treatment result?] / Hüftdysplasie im Grenzbereich: Welchen Einfluss haben Alter, Arthrose und Begleiterkrankungen auf das Behandlungsergebnis?

Pelvic osteotomies are an established treatment for symptomatic adult hip dysplasia with a promising long-term outcome. Results depend not only on the achieved acetabular reorientation but also on patient-factors like preoperative joint condition (degree of osteoarthritis and joint congruency) and age. Additionally, the diagnosis and appropriate therapy of impingement-associated hip deformities is essential in order to achieve good mid- and long-term outcomes. The influence of chondrolabral pathology on the outcome of pelvic osteotomies is not yet defined. Symptomatic patients with residual dysplasia after previous pelvic or acetabular osteotomies can benefit from an additional osteotomy, although results can be worse in comparison to prior unoperated joints. Obesity can make surgery more demanding and increases the complication profile of PAO, although it has no influence on the postoperative outcome. Regarding the overall prognosis after an osteotomy, the consideration of combined risk factors is superior to the concentration on individual factors alone.

[Strategies for cup revision]. / Strategien für die Pfannenrevision.

Hip arthroplasty revision management can range from simple procedures using standard implants to complex surgical interventions requiring the combined use of revision cups, metal augments, bone grafts, and antiprotrusio cages. The adequate restoration of biomechanics and function of the hip joint with reconstruction of the original center of rotation can be challenging. We present an overview of various available techniques with the associated implant and anchoring strategies and the respective clinical results depending on the acetabular defect situation.

Dual-Mobility Cups in Primary Total Hip Arthroplasty. / Tripolare Pfannen in der Primärhüftendoprothetik.

Dual-mobility cups (DMCs) were introduced in France more than 40 years ago and are increasingly used not only in hip revision but also primary hip arthroplasty. Due to a simulated large-head articulation and increased jumping distance, DMCs can contribute to a high range of motion in the hip joint and reduce the risk of instability. Numerous studies have reported low dislocation rates and high survival rates in the mid-term follow-up. Nevertheless, long-term data, especially on primary hip replacement, remain limited, and the effect of recent designs and material innovations is still unclear. Therefore, primary DMCs are mainly proposed in patients at high risk for dislocation (i.e. pelvitrochanteric insufficiency, compromised spinopelvic mobility, neuromuscular disorders, obesity and femoral neck fractures). Based on a review of recently published studies referring to these indications, the current study discusses the advantages and disadvantages of DMCs.

Ultrasonic bone cement removal efficiency in total joint arthroplasty revision: A computer tomographic-based cadaver study.

Polymethylmethacrylate (PMMA) removal during septic total joint arthroplasty revision is associated with a high fracture and perforation risk. Ultrasonic cement removal is considered a bone-preserving technique. Currently, there is still a lack of sound data on efficacy as it is difficult to detect smaller residues with reasonable technical effort. However, incomplete removal is associated with the risk of biofilm coverage of the residue. Therefore, the study aimed to investigate the efficiency of ultrasonic-based PMMA removal in a human cadaver model. The femoral components of a total hip and a total knee prosthesis were implanted in two cadaver femoral canals by 3rd generation cement fixation technique. Implants were then removed. Cement mantle extraction was performed with the OSCAR-3-System ultrasonic system (Orthofix®). Quantitative analysis of cement residues was carried out with dual-energy and microcomputer tomography. With a 20 µm resolution, in vitro microcomputer tomography visualized tiniest PMMA residues. For clinical use, dual-energy computer tomography tissue decomposition with 0.75 mm resolution is suitable. With ultrasound, more than 99% of PMMA was removed. Seven hundred thirty-four residues with a mean volume of 0.40 ± 4.95 mm3 were identified with only 4 exceeding 1 cm in length in at least one axis. Ultrasonic cement removal of PMMA was almost complete and can therefore be considered a highly effective technique. For the first time, PMMA residues in the sub-millimetre range were detected by computer tomography. Clinical implications of the small remaining PMMA fraction on the eradication rate of periprosthetic joint infection warrants further investigations.

The incidence of adverse local tissue reaction due to head taper corrosion after total hip arthroplasty using V40 taper and 36 mm CoCr head.

AIMS: Head-taper corrosion is a cause of failure in total hip arthroplasty (THA). Recent reports have described an increasing number of V40 taper failures with adverse local tissue reaction (ALTR). However, the real incidence of V40 taper damage and its cause remain unknown. The aim of this study was to evaluate the long-term incidence of ALTR in a consecutive series of THAs using a V40 taper and identify potentially related factors. METHODS: Between January 2006 and June 2007, a total of 121 patients underwent THA using either an uncemented (Accolade I, made of Ti12Mo6Zr2Fe; Stryker, USA) or a cemented (ABG II, made of cobalt-chrome-molybdenum (CoCrMo); Stryker) femoral component, both with a V40 taper (Stryker). Uncemented acetabular components (Trident; Stryker) with crosslinked polyethylene liners and CoCr femoral heads of 36 mm diameter were used in all patients. At a mean folllow-up of 10.8 years (SD 1.1), 94 patients (79%) were eligible for follow-up (six patients had already undergone a revision, 15 had died, and six were lost to follow-up). A total of 85 THAs in 80 patients (mean age 61 years (24 to 75); 47 (56%) were female) underwent clinical and radiological evaluation, including the measurement of whole blood levels of cobalt and chrome. Metal artifact reduction sequence MRI scans of the hip were performed in 71 patients. RESULTS: A total of 20 ALTRs were identified on MRI, with an incidence of 26%. Patients with ALTR had significantly higher median Co levels compared with those without ALTR (2.96 µg/l (interquartile range (IQR) 1.35 to 4.98) vs 1.44 µg/l (IQR 0.79 to 2.5); p = 0.019). Radiological evidence of osteolysis was also significantly associated with ALTR (p = 0.014). Median Cr levels were not significantly higher in those with ALTR compared with those without one (0.97 µg/l (IQR 0.72 to 1.9) v 0.67 µg/l (IQR 0.5 to 1.19; p = 0.080). BMI, sex, age, type of femoral component, head length, the inclination of the acetabular component, and heterotopic ossification formation showed no significant relationship with ALTR. CONCLUSION: Due to the high incidence of local ALTR in our cohort after more than ten years postoperatively, we recommend regular follow-up investigation even in asymptomatic patients with V40 taper and metal heads. As cobalt levels correlate with ALTR occurrence, routine metal ion screening and consecutive MRI investigation upon elevation could be discussed. Cite this article: Bone Joint J 2022;104-B(7):852-858.

Outcome-Affecting Parameters of Hip Arthroscopy for Femoroacetabular Impingement with Concomitant Cartilage Damage-Data Analysis from the German Cartilage Registry.

This study aims to report on a prospectively collected, multicenter database of patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAI) and concomitant cartilage damage (according to the International Cartilage Repair Society) and to assess the outcome-affecting parameters. In the study, 353 hips with up to 24 months' follow-up were assessed by iHOT-33 scoring and achievement of the minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) levels. Multiple and binary regression analyses were performed to identify factors related to (un-) favorable outcomes and to assess their clinical relevance with regard to achieving the MCID and PASS. Multiple regression yielded the parameters of male sex (p = 0.022) and lower body mass index (BMI) (p = 0.019) at 6 months, lower BMI (p = 0.022) and younger age (p = 0.022) at 12 months, and younger age at 24 months (p = 0.039) to be significantly associated with higher iHOT scoring. Male sex (p = 0.019) and lower BMI (p = 0.018) were significantly correlated with achievement of the PASS in binary regression at 6 months, whereas at 12 (p = 0.010) and at 24 (p = 0.003) only younger age was shown to be significantly correlated. None of the parameters was statistically associated with achievement of the MCID. As the parameters of younger age, male sex, and lower BMI were identified as temporarily correlated with a preferable outcome in general and with achievement of the PASS in particular, these findings help to preoperatively identify factors associated with (un-) favorable therapy results.