Isolated Femoral or Tibial Component Revision in Total Knee Arthroplasty: A Systematic Review.

OBJECTIVE: The purpose of this systematic review is to assess clinical and radiographic outcomes, complications rates, rates and reasons of re-revision of isolated femoral or tibial component revisions, comparing them with total knee revisions. METHODS: A review of the published literature was performed using Medline, Embase and Cochrane libraries. The terms "isolate" and "revision" and "knee arthroplasty" or "knee replacement" were together used as MESH terms. Partial knee replacement, non-English literature, case reports and papers published before 2000 were excluded. RESULTS: Out of 911 papers, six papers met the inclusion criteria. Mean MINORS scores achieved quite low values (13.33 and 13.67). No study encompassed revisions for septic loosening or infection. Total revisions performed for instability and wear achieved better clinical outcomes: in the other cases, partial and total revisions showed no differences in clinical outcomes. Both the cohorts showed similar radiographic features. Lesser bleeding and shorter operative times were observed in partial revisions compared to total revisions. The re-revision rates were similar in most of comparative studies: only one study noticed a significant difference in the failure rate between partial (25% at 3 years) and full (7% at 3.5 years) revisions. CONCLUSIONS: The poor quality of the studies precluded sound conclusions. Isolated tibial or femoral component revision is an option when the other component is well-fixed and positioned and in absence of chronic periprosthetic infection; nevertheless, it should be carefully evaluated when the reasons for revision are wear or instability.

Hip Labral Morphological Changes in Patients with Femoroacetabular Impingement Speed Up the Onset of Early Osteoarthritis.

Over the last decade, evidence has mounted for a prominent etiologic role of femoroacetabular impingement (FAI) in the development of early hip osteoarthritis (OA). The aim of this study was to compare the ultrastructure and tissue composition of the hip labrum in healthy and pathological conditions, as FAI and OA, to provide understanding of structural changes which might be helpful in the future to design targeted therapies and improve treatment indications. We analyzed labral tissue samples from five healthy multi-organ donors (MCDs) (median age, 38 years), five FAI patients (median age, 37 years) and five late-stage OA patients undergoing total hip replacement (median age, 56 years). We evaluated morpho-functional by histology and transmission electron microscopy. Extracellular matrix (ECM) structure changes were similar in specimens from FAI compared to those from patients with OA (more severe in the latter) showing disorganization of collagen fibers and increased proteoglycan content. In FAI and in OA nuclei the chromatin was condensed, organelle degenerated and cytoplasm vacuolized. Areas of calcification were mainly observed in FAI and OA labrum, as well as apoptotic-like features. We showed that labral tissue of patients with FAI had similar pathological alterations of tissue obtained from OA patients, suggesting that FAI patients might have high susceptibility to develop OA.

Mid-term outcomes of revision hip arthroplasty due to titanium modular neck failure.

INTRODUCTION: The current strategy for modular neck failures in total hip arthroplasty (THA) is calibrated on CrCo neck failures. Stem revision is usually required, but the procedure is challenging and achieves modest outcomes (up to 20% of re-revisions at short-term). No study reports revision strategies and outcomes after Ti neck failures. Aims of the study were to evaluate: (1) demographic and implant features of the cohort to be revised, (2) intra-operative findings and surgical revision strategies and (3) clinical and radiological post-revision outcomes. MATERIALS AND METHODS: Hospital database was enquired about revisions due to Ti neck failures in primary THAs. Sixty-five revisions were enrolled (all with the same modular system). Neck exchange was attempted as the first-line treatment. Patients were clinically and radiographically evaluated after revision. RESULTS: The revision cohort encompassed fatigue neck fractures occurred 4.4 ± 2.6 years after THA: patients < 65 years and/or > 80 kg (98.5%) were predominant. Fifty-three neck exchanges were performed (81.5%). Eleven failures required stem revisions (16.9%), generally due to demanding neck extraction. Six complications occurred after neck exchange (11.3%), among them 2 acute infections requiring surgery (3.8%). Among stem revisions, one aseptic loosening and one neck re-fracture (18.5%) required re-revisions. At a mean follow-up of 7.1 ± 4 years, the neck exchange cohort achieved a mean HHS of 89.1 ± 6.3 (stem revisions: 84.1 ± 10.9). CONCLUSIONS: Revisions for Ti neck failures were predominantly performed due to fatigue fractures. In case of failures, neck exchange is a feasible procedure in most of the cases, with good outcomes at 7 years. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Comparison of single taper and dual taper versions of the same stem design in total hip arthroplasty for primary osteoarthritis.

BACKGROUND: In total hip arthroplasty (THA), the outcomes of single taper (ST) and dual taper (DT) versions of the same stem design have been scarcely studied. A registry study comparing ST and DT versions of the same stem design was designed, aiming to assess: (1) the survival rates and the hazard ratios for failure; (2) the survival rates and the hazard ratios for failure using stem-focused endpoints. MATERIAL AND METHODS: A regional arthroplasty registry was interrogated about stem designs with ST and DT versions in cementless THAs performed for primary osteoarthritis. Only the same cup and ceramic-on-ceramic bearings were included: the DT stems had a titanium-on-titanium modularity. Demographic and implant features were recorded. Survival rates and hazard ratios were evaluated and compared. Stem-focused endpoints were also investigated. RESULTS: A total of 5359 THAs were included, with three stem designs. The two versions of every stem showed different demographics and implant-related features: ST versions were preferentially implanted in heavier young men. For each stem, the two versions had similar survival rates at 5 years (p = 0.076; p = 0.319; p = 0.616) and similar adjusted hazard ratios for failures (p = 0.084; p = 0.308; p = 0.729). When stem-focused endpoints were adopted, the ST and DT versions of the three stems achieved similar survival rates (p = 0.710; p = 0.784; p = 0.983) and similar adjusted hazard ratios (p = 0.647; p = 0.858; p = 0.787). Three neck breakages occurred (0.0007% of all the modular implants). CONCLUSIONS: ST and DT versions of the same stem design did not show any differences in terms of survival rates and hazard ratios for failures at 5 years. LEVEL OF EVIDENCE: IV.

Software-related recalls in computer-assisted hip and knee arthroplasty.

PURPOSE: Computer-assisted arthroplasty supports the surgeons in planning, simulating, and performing the replacement procedure, using robotic or navigation technologies. However, the safety of the technology has not been widely ascertained. Food and Drug Administration (FDA) database was interrogated about software-related recalls in computer-assisted arthroplasty, aiming to assess: (1) the incidence, (2) the root causes, and (3) the actions taken due to recalls. METHODS: The Medical Device Recalls database was investigated about software-related recalls in computer-assisted hip and knee arthroplasty surgery, between 2017 and 2022. The incidence of the software-related recalls, the root causes according to FDA and manufacturers, and the corrective actions taken by firms were determined. RESULTS: Eighteen recall numbers could be identified (1.6%), corresponding to 11 recall events. A total of 4634 units were involved. The FDA determined root causes were: software design (66.6%), design change (22.2%), manufacturing deployment (1, 5.6%), and design manufacturing process (5.6%). Among the manufacturers' reasons for recalls, a specific error was declared in 16 cases (88.9%). In seven cases (43.8%), a coding error about lower limb alignment assessment was identified. Seventeen software-related recalls (94.4%) were classified as class 2; only one case was class 3 (5.6%). Return of the device was the main action taken by firms (8, 44.4%), followed by software update (7, 38.9%). CONCLUSION: Software-related recalls in computer-assisted hip and knee arthroplasty were quite uncommon among all the recalls, deemed non-life threatening and usually due to software design errors. The main actions taken by manufacturers were the return of the device or the software update.

Cup Overhanging in Anatomic Socket Position or High Hip Center of Rotation in Total Hip Arthroplasty for Crowe III and IV Dysplasia: A CT-Based Simulation.

Cup overhanging in total hip arthroplasty is a predisposing factor to iliopsoas impingement. In dysplastic hips, cup implantation was simulated in an anatomic hip center of rotation (AHCR) and in high hip center (HHCR). We sought to assess: (1) the percentage of prominent cups; (2) quantify the cup protrusion at different sites on frontal, axial and sagittal views. In 40 Crowe III-IV hips, using a 3D CT-based planning software, cup planning in AHCR and HHCR (CR height ≥ 20 mm) was performed for every hip. Cup prominence was assessed on every plane. HHCR cups were less anteverted (p < 0.01), less medialized (p < 0.001) and less caudal (p = 0.01) than AHCR sockets. AHCR cups were more frequently prominent on at least one plane (92.5% vs. 77.5%), with minimal agreement between the two configurations (k = 0.31, p = 0.07). AHCR cups protruded more than HHCR sockets in the sagittal (p = 0.02) and axial planes (p < 0.001). Axially, at the center of the cup, prominence 6−11 mm occurred in nine (22.5%) AHCR and one (2.5%) HHCR socket. In conclusion, while a routine high hip center should not be recommended, cup placement at a center of rotation height < 20 mm is associated with higher rates and magnitudes of anterior cup protrusion in severe dysplasia.

Correlation Between Co Levels in Hair and Blood of Patients Who Underwent Metal-on-metal Hip Arthroplasty.

Background: The purpose of this paper is to study the dependence of Co levels in hair on Co levels in blood after metal-on-metal (MoM) hip replacement and prove the suitability of hair analysis coupled to blood analysis in the decision process regarding implant revision evaluation. Methods: Hair samples of 19 MoM patients having both well-functioning and malfunctioning implants and Co mass concentration levels in blood between 0.2 µg L-1 and 221.0 µg L-1 were included. A method based on inductively coupled plasma mass spectrometry was validated and used to measure the Co level in hair. Results: The Co mass fraction in the hair of patients ranged between 0.011 mg kg-1 and 0.712 mg kg-1. A correlation analysis showed a statistically significant positive correlation (r = 0.932, P < .001) between Co in the hair and that in the blood in the full-level range and a statistically nonsignificant positive correlation (r = 0.595, P = .091) in the low-level range. Conclusions: A correlation between the Co level in the hair and that in the blood exists when the latter is clearly above the 7 µg L-1 mass concentration threshold suggested for implant revision evaluation. The correlation disappears when the Co level in blood approaches or falls down the mass concentration threshold and that in the hair approaches or falls within the normal population range of 0.004-0.14 mg kg-1. Accordingly, clinicians could consider a hair analysis coupled to a blood analysis to assess the revision of malfunctioning MoM implants that release metals in patient's body.

Isolated arthroscopic treatment of intra-articular pathologies in mild hip dysplasia: a short-term case control study.

PURPOSE: The aim is to compare the results of isolated hip arthroscopy in patients with borderline dysplasia with Lateral center edge angle (LCEA) between 18° and 25° with a control group of patients with normal LCEA (> 25°). METHODS: Fifty hip arthroscopies performed in 45 patients were retrospectively evaluated. Exclusion criteria were: age > 40, hip arthritis > grade 2 according to Tonnis classification, femoral head avascular necrosis, pediatric's orthopaedics conditions and true dysplasia with LCEA < 18°.Two groups were identified: group A with 15 hips with LCEA between 25° and 18° and Group control B made of 35 hips with LCEA > 25°. RESULTS: The groups were homogeneous for demography and pre-operative WOMAC and HOOS. Osteoplasty for CAM were performed in 100% of patients in both groups, only in 12 hips (34.4%) in group B we had both femoral and acetabular osteoplasty. Labral repair was performed in 86% of patients in group A, in 60% of patients in group B, capsular plication in 93% of group A, in 5% of case of group B. WOMAC and HOOS statically significant improved in both groups at final follow-up (24 months). No cases in both groups required conversion to total hip arthroplasty. Clinical outcomes of study group were comparable to the control group. CONCLUSION: Even if the present small series is not conclusive, we suggest isolated arthroscopic management of patients with FAI and LCEA between 18° and 25°, but capsular plication and careful labral management are strongly recommended. LEVEL OF EVIDENCE: Level IV.

Measuring stem anteversion after total hip arthroplasty: posterior condylar tangent versus transepicondylar axis.

OBJECTIVE: Stem anteversion in total hip arthroplasty (THA) has been measured using two different distal references, the posterior condyle (PC) or the transepicondylar axis (TEA). The reliability, the difference in value between these two techniques, and the possible confounding factors are scarcely known. Aims of this work were to assess (1) the intraclass correlation and the difference between the two measurement techniques and (2) the possible influence of condylar dysmorphisms on the anteversion value discrepancy. MATERIALS AND METHODS: A consecutive series of post-THA CT scans were selected, excluding hip dysplasia, end-stage knee osteoarthritis, and replaced knees. Using a surgical planning software, stem anteversion was measured using the PC or the TEA reference. The intraclass reliability was assessed. The anteroposterior femoral condyle diameters were measured: the difference and the ratio were measured and correlated with the stem anteversion values. RESULTS: 91 CT scans were included. Inter/intra-observer TEA measurements were more reliable than PC. The intraclass correlation between PC and TEA anteversion measurements was good, 0.954 (CI 95% 0.922-0965). The mean difference between PC and TEA anteversion was 5.27 ± 2.41°. The difference and the ratio between the two anteroposterior condyle diameters did not influence the anteversion difference (respectively, p 0.797 and p 0.901). CONCLUSIONS: TEA and PC demonstrated to achieve a good correlation, not dependent from the condyle morphology. However, the difference between the two measurements (5°) can severely influence the combined anteversion (10-20%): due to clinical applicability and better inter/intra-observer agreement, TEA should be preferred for measuring stem anteversion.

Cementless ceramic-on-ceramic total hip arthroplasty in post-traumatic osteoarthritis after acetabular fracture: long-term results.

INTRODUCTION: Total hip arthroplasty (THA) is the standard procedure for post-traumatic osteoarthritis (OA) of the hip after acetabular fracture. However, it is not as simple as a primary THA, challenging the surgeon with anatomical deformity and intra and postoperative complications. In the current literature, there is a lack of studies reporting long-term results. May ceramic-on-ceramic (CoC) bearings provide good clinical and radiological outcomes at a long-term follow-up in patients undergoing THA following acetabular fracture? MATERIALS AND METHODS: We retrospectively analyzed 68 patients (mean age 47 years [range 22-75)] who underwent cementless modular neck stem THA, all implants CoC bearings (50 previously operatively treated and 18 non-operatively treated) after a specific CT study protocol at our Institute since 2000-2008. Clinical outcomes, prosthetic components' osseointegration, survival rate, and reasons for revision were analyzed. Minimum clinical and radiological follow-up was 10 years. RESULTS: HHS improved significantly after surgery from 37.6 ± 14.1 to 88.4 ± 11.6. 8 revision surgeries were performed, none for infection: we reported 2 stem aseptic loosening, 2 periprosthetic femoral fractures and 4 modular neck fractures. One implant noise (third-generation ceramic coupling) was described. Cup osseointegration was present (according to Moore the presence of at least 3 radiological criteria defines an effective osseointegration) in 67 patients (98.5%). After a 10 years follow-up, survival rate resulted 88.4%, sensibly higher than most of results reported in the current literature. CONCLUSION: The high survival rate may be related to CoC: no osteolysis and no infections were reported. Also acetabular cup loosening incidence was sensibly lower (1.47%) among loosening rate described by other authors. Clinical and radiological outcomes were decent, probably due to modular prosthesis design. Modular necks are a solution which can help achieving a proper functional reconstruction of the hip (offset, center of rotation), but should be avoided in young and overweight patients because of the high risk of fracture. CoC bearings in THAs in post-traumatic OA after acetabular fracture showed good results despite the fact that specific ceramic-related issues have to be considered.

Arthroscopic tendon release for iliopsoas impingement after primary total hip arthroplasty: a retrospective, consecutive series.

INTRODUCTION: Aim of this study was to describe the clinical outcomes of 16 patients with iliopsoas (IP) impingement after primary total hip arthroplasty (THA), treated with an arthroscopic tendon release. METHODS: 16 patients (11 females/5 males), with a mean age of 57.8 ± 11.1 years (age at THA: 54.4 ± 11 years) and a diagnosis of IP impingement after primary THA, were treated with the Wettstein tenotomy. Preoperatively, every patient underwent a diagnostic ultrasonography guided peritendinous injection and a computed tomography (CT) scan. Every patient was clinically evaluated using WOMAC score. Subjective pain relief and active hip flexion strength were measured. RESULTS: No complications related to arthroscopy were detected. Every cup was prominent with a mean axial overhang of 13 ± 4.8 mm (range 5-20 mm). At a mean follow-up of 27 ± 20.1 months (range 6-48 months), the WOMAC score was 83.7 ± 10.1 points. 13 patients out of 16 (81.3%) had a complete pain relief. 14 patients out of 16 (88%) regained full active hip flexion strength at the final follow-up. 1 patient was scheduled for cup revision after 6 months, due to persistent symptomatology. No demographic data or CT measurements about cup position statistically influenced the outcome. CONCLUSIONS: When preceded by an appropriate diagnosis, arthroscopic tenotomy proved safe and effective for IP impingement, regardless the magnitude of cup protrusion.

Abductor muscle strengthening in THA patients operated with minimally-invasive anterolateral approach for developmental hip dysplasia.

OBJECTIVE: In developmental hip dysplasia (DDH) patients, the chronic dislocation of the femoral head with respect to the true acetabulum determines muscle contracture and atrophy, particularly of the abductor muscles, and leads to secondary osteoarthritis (OA) with severe motor dysfunction, pain and disability. The correct positioning when a total hip replacement (THR) is performed is fundamental to the recovery of gait function. Also, inadequate rehabilitation of the abductor muscles for pelvic stabilisation can be responsible for residual dysfunction. Consensus on a programme for abductor muscle strengthening in these patients is not currently available. The aim of this study was to evaluate the effectiveness of a specific program of exercises for strengthening the abductor muscles in these patients. METHODS: A multicentre, prospective, randomised clinical trial was carried out in an outpatient rehabilitation setting on 103 patients given THR for DDH through a minimally-invasive anterolateral approach. Patients were randomly divided into a Study Group, including 46 patients, and a Control Group, including 57 patients. All patients underwent standard early postoperative rehabilitation. In addition, the Study Group were given an extra 2-week rehabilitation once full weight-bearing on the operated limb was allowed, aimed at strengthening the abductor muscles. All patients were evaluated preoperatively, and at about 3 and 6 months postoperatively. Clinical measures (lower limb-length differences, hip range of motion, abductor muscle strength), and functional measures (WOMAC, HHS, 10mt WT, SF-12) were taken. RESULTS: Hip range of motion and functional outcome measures showed a progressive improvement at follow ups in both groups, significantly higher in the Study Group. In particular, abductor strength at 6 months post-op improved by 92.5% with respect to 35.7% in the Control Group. CONCLUSION: In addition to standard rehabilitation, a rehabilitation programme for strengthening the gluteal muscles in DDH patients who underwent THR determined an increase in muscle strength that improved functional performance and patient satisfaction.

lsolated acetabular revisions of articular surface replacement (ASR) XL implants with highly porous titanium cups and Delta bearings.

INTRODUCTION: Articular surface replacement (ASR) XL implants exhibit higher-than-expected revision rates, blood ion concentrations and soft tissue lesions, making revisions troublesome and potentially unsatisfying. Appropriate techniques and outcomes in ASR XL revisions are rarely documented. The aims of this study were the assessments of pre-revision data, post-revision clinical and radiographic outcomes and ion levels in isolated acetabular ASR XL revisions performed using highly porous titanium cups and Delta ceramic articulations. METHODS: 18 isolated acetabular ASR XL revisions in 16 patients were performed using Ti-Por cups (Adler Ortho, Milan, Italy) and Delta bearings (CeramTec, Plochingen, Germany). Pre-revision demographic, clinical, radiological and implant-related features were assessed. Clinical and radiographic parameters (cup positioning, osseointegration) after revisions were evaluated at a minimum follow-up of 5 years. Ion concentrations in blood and urine were collected in pre-revision setting and 1 year after revision. RESULTS: 4 complications occurred in 3 different revisions (16.7%), 1 dislocation, 2 infections, 1 psoas impingement. No re-revision was performed at 5 years (1 scheduled arthroscopy). Good clinical outcomes were achieved (HHS score: 88.3 ± 9.2). All the cups showed reassuring signs of osseointegration (>3 parameters). Blood ion concentrations significantly decreased: patients with Co blood ion concentration over the threshold (7 µg/l) decreased from 76.5% to 0%. No pre-revision or intraoperative data influenced the revision outcomes. CONCLUSIONS: Highly porous titanium cups and Delta ceramic articulations provided reliable mid-term clinical and radiographic outcomes in isolated acetabular ASR XL revisions. Ion concentrations significantly decreased. Multicentre prospective controlled studies are required to confirm these preliminary outcomes.

Labral calcification plays a key role in hip pain and symptoms in femoroacetabular impingement.

BACKGROUND: Hip osteoarthritis (HOA) is the most common hip disorder and a major cause of disability in the adult population, with an estimated prevalence of end-stage disease and total hip replacement. Thus, the diagnosis, prevention, and treatment of the early stages of the disease in young adults are crucial to reduce the incidence of end-stage HOA. The purpose of this study was to determine whether (1) a relationship among the inflammatory status of labrum and synovium collected from patients with femoroacetabular impingement (FAI) would exist; and (2) to investigate the associations among the histopathological features of joint tissues, the pre-operative symptoms and the post-operative outcomes after arthroscopic surgery. METHODS: Joint tissues from 21 patients undergoing hip arthroscopy for FAI were collected and their histological and immunohistochemical features were correlated with clinical parameters. RESULTS: Synovial mononuclear cell infiltration was observed in 25% of FAI patients, inversely correlated with the hip disability and osteoarthritis outcome score (HOOS) pain and function subscales and with the absolute and relative change in total HOOS. All the labral samples showed some pattern of degeneration and 67% of the samples showed calcium deposits. The total labral score was associated with increased CD68 positive cells in the synovium. The presence of labral calcifications, along with the chondral damage worsened the HOOS post-op symptoms (adjusted R-square = 0.76 p = 0.0001). CONCLUSIONS: Our study reveals a relationship between the histologic labral features, the synovial inflammation, and the cartilage condition at the time of FAI. The presence of labral calcifications, along with the cartilage damage and the synovitis negatively affects the post-operative outcomes in patients with FAI.

Delta-on-Delta Ceramic Bearing Surfaces in Revision Hip Arthroplasty.

BACKGROUND: Fourth-generation ceramic-on-ceramic couplings were developed to improve ceramic toughness and strength. Encouraging outcomes in primary total hip arthroplasty were reported. This coupling was proposed as an attractive option even in the case of revision procedures, particularly in younger patients with a longer life expectancy. However, the pertinent literature is scarce. Thus, a registry study was conducted to investigate the midterm survival rates and reasons for re-revision of the fourth-generation ceramic-on-ceramic bearing surfaces in revision hip arthroplasties. METHODS: A total of 327 revision implants (all the components were exchanged) with BIOLOX Delta couplings were investigated using the regional orthopedic registry RIPO. The demographics, the survival rates, and the reasons for re-revision were assessed. Revisions with bearings other than Delta were compared. RESULTS: Delta bearings achieved a survival rate of 90.5% at 7 years, with stable results. Twenty-six (8%) re-revisions occurred at a mean follow-up of 4.1 years. And 2.8% of the re-revisions were due to recurrent dislocations; 1.5% of the cases were due to cup aseptic loosening. Septic loosening occurred in 1.6% of the cases. No ceramic fractures were reported. When compared to revisions with bearings other than Delta-on-Delta, Delta coupling cohort achieved similar performances at 5 and 7 years. Lower, nonsignificant rates of aseptic and septic loosening were reported in Delta cohort. CONCLUSION: Delta-on-Delta couplings demonstrated to be reliable bearing surfaces in revision settings at a midterm follow-up. Clinical studies and longer follow-ups are required to investigate potential adverse effects, like squeaking and fractures, and confirm these preliminary findings. LEVEL OF EVIDENCE: Level III, therapeutic study.

Cementless Total Hip Arthroplasty in Crowe III and IV Dysplasia: High Hip Center and Modular Necks.

BACKGROUND: Total hip arthroplasty (THA) in severe developmental dysplasia of the hip (DDH) is a challenging procedure. The most used techniques involve anatomic cup positioning, augmentation femoral osteotomy. However, anatomic cup positioning is not always feasible in severe DDH and osteotomy nonunion may ensue. The purpose of the study was to assess the survivorship, the hip score results, the radiological parameters (fixation, loosening, component position) of a large cohort of patients with Crowe III and IV DDH, treated with high hip center and modular necks THAs. METHODS: Eighty-four THAs in Crowe III and IV DDH were evaluated, achieving a final follow-up of 15.1 years. All the patients were treated with the same cementless implant (modular necks and ceramic-on-ceramic coupling) and the same approach (high cup placement with slight medialization). The patients were clinically evaluated (Harris Hip score and Merle d'Aubigne and Postel score). A radiographic evaluation was performed, analyzing the orientation of the cup. RESULTS: Eighty patients were available at the last follow-up. The clinical scores were good at the final follow-up. Two sciatic lesions occurred: one patient fully recovered. The overall survivorship was 90.5% at 15 years: only 2 cases of aseptic loosening were reported. The mean center of rotation height was 33 ± 8 mm and the medialization was 30 ± 5 mm. CONCLUSION: A high cup placement with slight medialization is a valid technique in DDH patients. A good restoration of the offset, ceramic-on-ceramic coupling and a porous socket may provide durable results, overcoming the effects of increasing joint reaction forces related to high cup placement.

Total Knee Replacement in Young Patients: Survival and Causes of Revision in a Registry Population.

BACKGROUND: The incidence of total knee replacements (TKRs) in young patients is increasing. Few reports described encouraging results and acceptable survival rates. However, many concerns still persist, in particular about the high rates of infection and aseptic loosening. Aim of this article was to investigate the survival of TKRs in patients aged 45 years or younger in a registry population. METHODS: The Emilia-Romagna registry RIPO was enquired about TKRs in patients ≤45 years; 238 TKRs were evaluated at a mean follow-up of 5.4 years (range 0-15.6 years), examining the features of the patients involved, the survival rate, and the reasons for revision of the knee implants. RESULTS: The TKRs were generally performed in men, in private hospitals, and almost in half of the cases for other causes rather than primary osteoarthritis. The mean age was 40 years. Bicompartmental, cemented posterior-stabilized implants with fixed bearing were preferred. The survival rate was higher than 90% in the first 7 years, and then it decremented. The choice of implant did not apparently influence the survivorship. The final outcomes were acceptable, substantially in line with the previous literature about young patients. Twenty-one revisions occurred (8.8%), in particular 8 cases for aseptic loosening and 7 TKRs for infection. The rate of revision was higher than in overall population and even in some young cohorts. CONCLUSION: TKRs in patients aged 45 years or younger seem a promising procedure, although the high rates of septic and aseptic loosening should be carefully evaluated. Prospective, well-designed studies are required to confirm and investigate these preliminary findings.

Long-term results of total hip replacement in patients with Legg-Calvé-Perthes disease.

BACKGROUND: Total hip replacement in patients with Legg-Calvé-Perthes disease can be difficult because of the multiplanar deformities of the proximal part of the femur and previous surgery during childhood. The aim of the present study was to assess the long-term outcomes of total hip replacement in patients who had Legg-Calvé-Perthes disease during childhood. METHODS: A retrospective study was carried out to assess the results of thirty-two total hip replacements that had been performed for twenty-seven patients from January 1989 to November 2004. The average age at the time of surgery was 37.8 years. The average duration of follow-up was 124 months (range, fifty-eight to 248 months). All but one of the implants were cementless. RESULTS: There was only one failure in the present study; specifically, the one cemented stem in the study failed two years after surgery. The cumulative survival rate at fifteen years was 96.9% (95% confidence interval, 90.8% to 100.0%). The overall rate of complications was 12.5%, with two permanent sciatic nerve palsies. At the time of the latest follow-up, the average Harris hip score was 87.5 (range, 73 to 96), which was a marked improvement in comparison with the preoperative score (average, 50.1; range, 25 to 75). CONCLUSIONS: Despite the high rate of neurological complications, possibly related to excessive limb lengthening or inadequate soft-tissue release, total hip replacement can be considered a feasible option for patients with Legg-Calvé-Perthes disease. Careful preoperative planning is advisable in order to overcome the technical pitfalls related to the abnormal proximal femoral and acetabular anatomy of these patients.

Modular neck prostheses in DDH patients: 11-year results.

BACKGROUND: Total hip replacement in developmental dysplasia of the hip is a demanding procedure and usually requires dedicated devices and special surgical techniques. Nevertheless, the described techniques have shown variable outcomes. The aim of this study was to assess the 11-year outcomes of an off-the-shelf modular neck prosthesis in dysplastic patients and to evaluate the ability of the modular neck system to adequately restore femoral offset, abductor muscles lever arm and leg length. METHODS: We retrospectively evaluated 61 modular neck prostheses implanted in 47 patients between June 1995 and March 2004. The preoperative diagnosis was developmental dysplasia of the hip in all cases. The clinical outcomes were assessed using the Harris hip score and the Western Ontario and McMaster Universities score. The femoral offset, abductor muscles lever arm, height and medialization of the hip center of rotation, and differences in leg length were evaluated on postoperative radiographs. Prosthesis survival was calculated according to the Kaplan-Meier method considering any reason for revision as failure. The average follow-up was 117.2 months (range 57-162 months). RESULTS: The cumulative survival at 11 years was 97.5%. One prosthesis failed 5 years after surgery because of a ceramic liner fracture due to an inappropriate obstetric maneuver during labour. At the latest follow-up the mean Harris hip score was 74.7 (range 23-91). Leg length discrepancy was avoided in the majority of cases; femoral offset was almost always restored. CONCLUSIONS: The results of this series support the use of modular neck prostheses as an effective alternative in the treatment of developmental dysplasia of the hip. The modularity was very efficient in restoring offset, leg length and maintaining stability with a good mid-long-term follow-up. Unlike other proposed surgical techniques, these good results are achievable by a standard surgical technique and with an off-the-shelf prosthesis.