Revision of Failed Metal-on-Metal Total Hip Arthroplasty: Midterm Outcomes of 203 Consecutive Cases

BackgroundMetal-on-metal (MoM) revisions have shown high rates of complications from aseptic loosening, deep infection, and dislocation. The purpose of this study is to report on outcomes and complications of a large consecutive series of patients who were revised for failed MoM total hip arthroplasty (THA).MethodsWe evaluated 188 patients (203 hips) who underwent revisions of failed MoM THA. Mean age at the revision was 60 years old. Gender was female in 112 hips (55%) and male in 91 hips (45%). Mean interval to failure after primary THA was 4.9 years (range, 0-18 years). The acetabular component was revised in 183 cases (92%). Clinical outcomes assessed included pain score and Harris hip score.ResultsMean follow-up from revision was 4.2 years. Harris hip score improved from 53.6 pre-revision to 73.5 at most recent follow-up (P < .001). Pain level significantly improved from 17.2 pre-revision to 32.8 post-revision (P < .001). Reoperations occurred in 28 (14%) hips. Re-revision was required in 16 hips (7.9%). The most common reasons for re-revision were aseptic loosening (5), dislocation (3), infection (2), and iliopsoas tendonitis (2). Re-revision was significantly higher in cases of pseudotumor. There was no difference in survival with ultraporous cups. Three hips required re-revision to custom triflange components. All-cause survival was 90.5% at 4.2 years. Metal ion levels significantly declined after revision.ConclusionRevisions of failed MoM THA showed improvements in clinical outcomes, but present significant surgical challenges and complications especially in cases with soft tissue damage and pseudotumor.     

Uncemented Total Hip Arthroplasty Through the Direct Anterior Approach: Analysis of a Consecutive Series of 275 Hips With a Minimum Follow-Up of 10 Years

BackgroundThe 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.MethodsA 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.ResultsOf 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).ConclusionPrimary 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.     

Metal-on-Metal Hip Arthroplasty Does Equally Well in Osteonecrosis and Osteoarthritis

Many previous reports suggest total hip arthroplasty performs suboptimally in young patients with osteonecrosis. We retrospectively compared the performance of metal-on-metal articulation in a select group of 107 patients with 112 hips (98 uncemented and 14 cemented stems) 60 years of age or younger with either osteonecrosis (27 patients, 30 hips) or primary osteoarthritis (80 patients, 82 hips). We evaluated all patients with patient-generated Harris hip score forms and serial radiographs. Five mechanical complications were caused by impingement, two with pain, two dislocations, and one liner dissociation. At a minimum followup of 2.2 years (mean, 5.5 years; range, 2.2-11.7 years), we observed no osteolysis or aseptic loosening in the osteonecrosis group, whereas one osteoarthritic hip had cup revision for loosening (none showed evidence of osteolysis). None of the stems were loose. Patients with osteonecrosis or primary osteoarthritis were similar in clinical and radiographic performance. The patients with metal-on-metal hip arthroplasty for osteonecrosis had no revisions for aseptic loosening, but did have one liner change in a cup for painful impingement.     

Long-Term Outcomes After Metal-on-Metal Total Hip Arthroplasty With a 28-mm Head: A 17- to 23-Year Follow-Up Study of a Previous Report

Background

Second-generation, metal-on-metal total hip arthroplasty (MoM THA) using a 28-mm head has shown favorable results compared with large head MoM THA. The purpose of this study is to evaluate the long-term outcomes of cementless primary MoM THA with a 28-mm head and the incidence of osteolysis using computed tomography.

Does Revision of an Acetabular Shell With Insertion of an Uncemented Constrained Liner Confer Benefit Over Cementing Into a Well-Ingrown Shell?

BackgroundDuring revision total hip arthroplasty (THA), a constrained acetabular liner (CAL) may be inserted to enhance hip stability. It is unclear, however, whether cementation of a CAL into a retained cup offers an advantage compared to revision of the acetabular cup and insertion of an uncemented CAL. The purpose of our study was to compare outcomes and survivorship between the 2 methods.MethodsWe identified a total of 177 patients who underwent revision THA with a specific CAL at our center between July 2004 and May 2019 (114 cup revisions and insertion of an uncemented CAL, 63 cementations of a CAL into a retained cup). Kaplan-Meier (KM) survival analysis was performed for implant survival free from aseptic failure of the CAL for both cohorts.ResultsThe average follow-up time was 7.2 and 7.02 years for the cemented and uncemented cohort, respectively (P = .55). Five patients (7.93%) in the cemented CAL group experienced failure of the CAL, whereas 10 patients (8.77%) in the uncemented CAL cohort experienced failure (P = .21). Kaplan-Meier (KM) survival analysis demonstrated comparable survivorship at 10 years (P = .055).ConclusionThe results of our study suggest comparable survivorship between cementing a CAL into a retained cup and inserting an uncemented CAL in a revised acetabular cup. As a result of these findings along with the benefits associated with cementing a CAL, we encourage surgeons to readily consider this option in the management of recurrent instability.     

Fracture of the hip after knee arthroplasty--an unusual case with pain in the knee

Background?The long-term results of uncemented total hip arthroplasties vary widely due to differences in design, metal alloy, coating, surface structure, and porosity.

Patients and methods?We retrospectively studied 75 cementless Zweymüller SL stems in combination with Endler titanium-backed threaded cups (Z-E) in 70 patients. 35 patients were women, and the mean age at surgery was 52 (24–68) years. 16 patients died and 1 emigrated, 7 patients (of which 1 later died) subsequently underwent revision, and the remaining 47 patients with 50 original arthroplasties were followed up after a median of 16 (15–18) years.

Results?Revision of 8 hips resulted in an 18-year Kaplan-Meier estimated overall survival rate of 88% (CI: 79–96). 6 of 7 cup revisions were due to liner wear and osteolysis, and 1 was due to aseptic loosening. 2 of 3 stem revisions were due to femoral loosening and 1 was due to fracture of the neck of the stem. The clinical results were good, with a mean Harris hip score of 89 (54–100). Half of 70 hips in 65 patients had ectopic bone formation. All unrevised implants were radiographically stable, with a mean liner wear of 0.07 mm/year.

Interpretation?These long-term results demonstrate that the combination of a Zweymüller SL stem and an Endler titanium-backed screw cup is a good hip arthroplasty in young and active patients. A prefixed polyethylene liner is a drawback, necessitating exchange of the whole cup in cases with polyethylene wear.     

Dual Mobility and Conventional Bearings Have Comparably Low Dislocation Rates for Anterior-Based Approaches in Total Hip Arthroplasty

BackgroundDual mobility (DM) bearings for total hip arthroplasty (THA) have been proposed to reduce the risk of instability in select patients, especially those undergoing revision surgery. The use of DM bearings has not been studied as extensively for use in primary THA. The purpose of this study is to compare outcomes following primary THA with anterior-based approaches between patients receiving DM bearings vs standard bearing hip implants.MethodsWe retrospectively reviewed a consecutive series of patients undergoing primary THA through an anterior-based approach. A 3:1 propensity score match was performed between the standard and DM bearing patients to control for possible risk factors for instability. Functional outcomes, dislocations, and aseptic revisions were identified for each patient. The effect of DM on postoperative outcomes was determined using univariate statistical analyses.ResultsIn total, 250 DM bearings were compared to 753 standard bearings. We found no difference in dislocation rate between single bearings and DM bearings (0.53% vs 0.4%). There was 1 DM dislocation occurring in a liner with outer diameter of 38 mm. There were no DM dislocations with outer diameter >38 mm. Aseptic revision surgery was more common in DM. This difference was driven by higher incidence of femoral periprosthetic fracture. There were no differences in functional outcomes.ConclusionDislocation rates are comparably low between DM bearings and standard bearings for THA done using an anterior approach to the hip. Further investigation is needed to determine if specific patient populations may benefit from DM implants for primary THA when an anterior approach to the hip is being used.     

Ten-year results with the Morscher press-fit cup: an uncemented, non-modular, porous-coated cup inserted without screws

Total hip arthroplasty (THA) with well designed cementless acetabular implants has shown excellent results. The purpose of this study was to assess our clinical and radiological outcomes using an uncemented cup. We conducted a prospective cohort study including all consecutive primary THAs performed with the Morscher press-fit cup, an uncemented non-modular acetabular component, between March 1996 and December 1998. Patients were evaluated at ten years with clinical and radiological follow-up, patient satisfaction and questionnaire assessment using the Harris hip score (HHS), Merle d’Aubigné and Postel score, the UCLA score, the 12-item short-form health survey (SF-12) and a visual analog scale. Five hundred sixty-one THAs were performed in 518 patients. At 120 months (± 7.3 months), 303 patients with 335 THAs were still available for follow-up. None of the patients had required cup revision for aseptic loosening. At ten years, the cup survivorship was 98.8% (95% CI 97.4–99.5) with cup revision for any cause as an endpoint. No radiolucencies were seen around the cups, but osteolytic defects involved 21 stems (8.3%). Mean total linear polyethylene wear was 0.9 mm. The Morscher acetabular replacement cup provides excellent results at ten years. There were no revisions for aseptic loosening of the cup, and no osteolytic defects were found around the cup. Patient satisfaction was high and the clinical results were very good.     

Long-Term Results of Revision Total Hip Arthroplasty Using a Modern Extensively Porous-Coated Femoral Stem

BackgroundThe use of an extensively porous-coated uncemented cobalt-chrome monoblock femoral stem for revision total hip arthroplasty (THA) is well established with excellent mid-term results. The aim of this study is to report the long-term survivorship of these implants in femoral stem revisions.MethodsThis is a long-term retrospective review of prospectively collected data of 55 femoral stem revisions in 55 patients using a contemporary, cementless extensively porous-coated cobalt-chrome monoblock stem. All patients between 2001 and 2006 who underwent first time femoral stem revision with a contemporary, cementless extensively porous-coated cobalt-chrome monoblock stem were included. Harris Hip Score, Western Ontario and McMaster Universities Index, and University of California Los Angeles activity scores were recorded preoperatively and at latest follow-up. Radiographs were analyzed for evidence of loosening, subsidence, osteolysis, and bony union. This study included 55 patients, comprising of 36 females (66%) and 19 males (34%) with a mean age of 66.4 ± 9.3 years at the time of surgery. The mean time interval from index procedure was 9.8 ± 2.9 years. Mean time from revision THA to final follow-up was 13.2 ± 2.17 years with a minimum of 10 years of follow-up.ResultsIndications for revision included aseptic loosening (33), prosthetic joint infection (13), and periprosthetic fracture (10). Significant improvement in Harris Hip Score (85.1 ± 1.77 vs 51.8 ± 2.3, P < .001), Western Ontario and McMaster Universities Index (17.6 ± 0.77 vs 33.3 ± 0.8, P < .001), and University of California Los Angeles (5.25 ± 0.2 vs 2.7 ± 0.36, P < .001) scores were found at latest follow-up compared to preoperative. Fifty-four patients (98%) achieved stable bony ingrowth on radiographic analysis. All 10 patients treated for periprosthetic fractures achieved bony union of their fractures. Two patients suffered intraoperative periprosthetic fractures and were treated with a cable-plating system. There were no mechanical failures and no femoral stem re-revisions. One patient was diagnosed with a deep infection and was treated with chronic suppressive antibiotic therapy due to significant medical comorbidities.ConclusionRevision of the femoral component with a contemporary extensively porous-coated cobalt-chrome femoral stem has excellent functional outcomes, radiographic outcomes, and long-term survivorship with minimal complications.     

The Direct Anterior Approach for Total Hip Arthroplasty for Severe Dysplasia (Crowe III and IV) Provides Satisfactory Medium to Long-Term Outcomes

BackgroundThe direct anterior approach (DAA) is increasingly used for total hip arthroplasty (THA). Although the DAA can reduce pain, recovery time, and dislocations in nondysplastic hips, few studies report its results in patients with severe dysplasia. We aimed to evaluate outcomes of primary THA through the DAA with cup placement at the true acetabulum in hips with severe dysplasia.MethodsWe retrospectively evaluated 23 consecutive patients (29 hips) who underwent THA by DAA for osteoarthritis secondary to Crowe III-IV dysplasia. Surgical procedures were performed on a traction table, and the acetabular cup was placed in the true acetabulum. Patients were assessed clinically (complications, modified Harris Hip Score, Western Ontario and McMaster Universities Osteoarthritis Index, Oxford Hip Score) and radiographically (radiolucencies, subsidence, leg length discrepancies, cup inclination, and cup coverage) at a minimum of 2 years.ResultsOne patient (2 hips) died with original implants (at 13 and 14 years), 3 patients (3 hips) were revised due to wear-induced loosening (at 14, 16, and 18 years), and there were no dislocations or infections. The remaining 19 patients (24 hips) were assessed at 8.4 ± 4.7 years (range 2-20); 2 patients (2 hips) had complications that required reoperation without implant removal. The modified Harris Hip Score improved from 32 ± 9 to 94 ± 7, Western Ontario and McMaster Universities Osteoarthritis Index from 46 ± 18 to 90 ± 7, and Oxford Hip Score was 56 ± 4. Patients were very satisfied (90%) or satisfied (10%). Limb length discrepancy was 2.5 ± 9.0 mm.ConclusionTHA through the DAA with cup placement at the true acetabulum provides satisfactory mid to long-term clinical and radiographic outcomes compared to other approaches for hips with severe dysplasia.Level of EvidenceLevel IV, retrospective cohort study.     

The uncemented Bi-Contact total hip arthroplasty

We reviewed a consecutive series of 153 uncemented Bi-Contact (Aesculap, Tuttlingen, Germany) total hip arthroplasties (THAs) in 138 patients who had been followed for at least 5 years (mean, 6.8 years; range, 5-9 years). The Bi-Contact uncemented THA consists of a straight femoral stem made of titanium alloy. The proximal portion of the stem is titanium plasma-sprayed. The cup is press-fit with or without hydroxyapatite coating with a facility for anchoring screws with a snap-fit polyethylene liner. The mean age of the patients was 70.8 years (range, 41-94 years). The mean preoperative Harris hip score of 41 (range, 20-80) improved postoperatively to a mean of 92 (range, 56-96). Three acetabular cups were revised for aseptic loosening, and 1 cup was revised for recurrent dislocation. To date, none of the stems have been revised for aseptic loosening. Radiographic evaluation of the remaining 149 hips revealed that the acetabular cup was stable in 146 hips and possibly unstable in the remaining 3 cases with nonprogressive osteolysis behind the cup. None of the stems showed any evidence of instability. Using the recommendation of revision as the endpoint, the cumulative survival for the prosthesis was 97.3% at a mean follow-up of 6.8 years (95% confidence interval, 95.9-99.4), with stem survival of 100%. In the medium-term, these results are comparable to cemented primary THA and justify the continued use of this prosthesis.     

Dual-mobility cups in total hip arthroplasty after femoral neck fractures: A retrospective study comparing outcomes between cemented and cementless fixation

IntroductionTotal hip arthroplasty (THA) after femoral neck fracture (FNF) is associated with an increased risk of dislocation. The goals of our study were (1) to determine dislocation and revision rates when dual-mobility cups (DMCs) are used in these patients, (2) to analyze clinical and radiographic outcomes, survivorship, complications and mortality rate, and (3) to compare results between cemented and cementless cups.Patients and methodsWe retrospectively reviewed patients with FNF treated using DMC-THA between 2011 and 2018. A minimum 2-year follow-up was required for clinical and radiographic assessment. The clinical outcome was assessed using the Harris Hip Score (HHS) and Merlé D´Aubigné-Postel score (MDP). Radiolucent lines, osteolysis and cup loosening were analyzed.ResultsWe included 105 patients (105 hips) with a mean age of 75.5 years. There were no dislocations. One patient (1.0%) underwent cup revision at 39 months for aseptic cup loosening. The mean HHS and MDP were 80.5 and 14.2 respectively at a mean follow-up of 4.1 years. A higher MDP was found in patients with cementless rather than cemented cups (15.0 vs. 13.1; p = 0.006). Four patients had radiolucent lines > 1 mm, around cemented cups. At 6.8 years, estimated cup survival was 98.2% for revision for aseptic loosening and 97.3% for revision for any reason. The mortality rates were 6.7% at 1 year and 23.8% at last follow-up.ConclusionOur findings suggest that using DMC in THA for FNF may prevent dislocation with a low revision rate. Cementless cups had a higher MDP than cemented cups.     

Dual Mobility for Monoblock Metal-on-Metal Revision—Is It Safe?

BackgroundRevision of monoblock metal-on-metal (MoM) total hip arthroplasty (THA) is associated with high complication rates. Limited revision by conversion to a dual mobility (DM) without acetabular component extraction may mitigate these complications. However, the concern for polyethylene wear and osteolysis remains unsettled. This study investigates the results of DM conversion of monoblock MoM THA compared to formal acetabular revision.MethodsOne hundred forty-three revisions of monoblock MoM THA were reviewed. Twenty-nine were revisions to a DM construct, and 114 were complete revisions of the acetabular component. Mean patient age was 61, 54% were women. Components used, acetabular cup position, radiographic outcomes, serum metal ion levels, and HOOS Jr clinical outcome scores were investigated.ResultsAt 3.9 years of follow-up (range 2-5), there were 2 revisions (6.9%) in the DM cohort, 1 for instability and another for periprosthetic fracture. Among the formal acetabular revision group there was a 20% major complication rate (23/114) and 16% underwent revision surgery (18/114) for aseptic loosening of the acetabular component (6%), deep infection (6%), dislocation (4%), acetabular fracture (3%), or delayed wound healing (6%). In the DM cohort, there were no radiographic signs of aseptic loosening, component migration, or polyethylene wear. One DM patient had a small posterior metadiaphyseal femur lesion that will require close monitoring. There were no other radiographic signs of osteolysis. There were no clinically significant elevations of serum metal ion levels. HOOS Jr scores were favorable.ConclusionLimited revision with conversion to DM is a viable treatment option for failed monoblock MoM THA with lower complication rates than formal revision. Limited revision to DM appears to be a safe option for revision of monoblock MoM THA with a cup in good position and an internal geometry free of sharp edges or articular surface damage. Longer follow-up is needed to demonstrate any potential wear implications of these articulations.     

Total hip arthroplasty for rheumatoid arthritis in younger patients: 2,557 replacements in the Finnish Arthroplasty Register followed for 0–24 years

Background?The results of total hip arthroplasty (THA) in young patients with rheumatoid arthritis (RA) have been reported in only a few studies. On a nationwide level, the outcome of THA in these patients is unknown. We evaluated the population-based survival of THA in patients under 55 years of age with RA and factors affecting the survival.

Patients?Between 1980 and 2003, 2,557 primary THAs performed for RA in patients less than 55 years of age were reported to the Finnish Arthroplasty Register.

Results?Proximally circumferentially porous-coated uncemented stems had a 15-year survival rate of 89% (95% CI 83–94) with aseptic loosening as endpoint. The risk of stem revision due to aseptic loosening was higher with cemented stems than with proximally porouscoated uncemented stems implanted during the same period (RR 2.4; p < 0.001). In contrast, Cox regression analysis showed that the risk of cup revision was significantly higher for all uncemented cup concepts than for all-polyethylene cemented cups with any cup revision as endpoint. There were no significant differences in survival between the THR concepts.

Interpretations?Uncemented proximally circumferentially porous-coated stems and cemented all-poly-ethylene cups are currently the implants of choice for young patients with RA.     

Minimum 25-Year Results of a Tapered Titanium Porous Plasma Spray Coated Femoral Component

BackgroundPrevious studies have reported excellent results with tapered, titanium, porous plasma-sprayed components in patients undergoing uncemented primary total hip arthroplasty (THA). The purpose of this study was to examine survival and clinical results at a minimum 25-year follow-up.MethodsWe reviewed all patients who underwent primary THA at our center through 1995 with a specific femoral component that was essentially unchanged since its 1984 introduction, except porous coating was continued circumferentially in 1987, a hydroxyapatite-coated option was offered in 1988, and an offset option was added in 1999. There were 332 patients (396 THA) who had a minimum 25-year follow-up (range, 25 to 37). Mean age at surgery was 48 years (range, 21 to 70 years). Mean follow-up in nonfailed patients was 29 years (range, 25 to 37 years).ResultsThere were 31 femoral revisions (7.8%): 9 infections, 3 failures of ingrowth, 5 aseptic loosening, 8 osteolysis well-fixed, 2 periprosthetic fractures, 2 polyethylene wear with trochanteric avulsion, 1 component breakage, and 1 malalignment well-fixed. Kaplan-Meier survival with the endpoint of all-cause stem revision was 94.8% (95% confidence interval: ±0.9%) at 37 years, and with the endpoint of aseptic loosening/failure of ingrowth was 98.7% (95% confidence interval: ±0.5) at 37 years. Harris hip scores improved significantly from 43 preoperatively to 76 most recently.ConclusionThis tapered, titanium, porous plasma spray-coated femoral component continues to demonstrate high long-term survival with a low rate of femoral component revision for any reason or aseptic loosening/failure of ingrowth.     

非骨水泥臼杯加自体股骨头植骨全髋关节置换术治疗髋臼发育不良伴骨性关节炎

目的：评价非骨水泥臼杯加自体股骨头植骨的全髋关节置换术治疗髋臼发育不良继发骨性关节炎的结果。方法：回顾性分析20例(21髋)患者行全髋关节置换术治疗髋臼发育不良继发骨性关节炎。女性18例,男性2例,平均年龄50岁,采用非骨水泥臼杯加自体股骨头植骨螺钉固定重建髋臼侧。臼杯置于真性髋臼水平,所有病例由于髋臼缺损而需要行自体股骨头植骨。平均植骨块覆盖的臼杯比例为31％(10％～45％)。8髋植骨块覆盖小于25％,13髋位于25％-50％之间。平均随访时间4．7年(1．5—8年)。采用改良Harris评分对结果进行评估。术前及随访时进行摄片观察。结果所有植骨块均获得愈合。无植骨块塌陷和髋假体松动。改良Harris评分由术前平均46分增加到89分。术前除1例双髋发育不良外,下肢不等长均超过2cm,术后只有2例仍有双下肢不等长超过1cm。3髋的植骨块外侧非支撑臼杯部分出现轻微的骨吸收。3髋发现有BrookerⅠ度异位骨化,1髋Ⅱ度异位骨化。结论：使用非骨水泥臼杯加自体股骨头植骨重建髋臼侧的全髋关节置换术治疗髋发育不良继发骨性关节炎可获得良好结果。该方法在植骨块支撑臼杯不超过50％的情况下,髋臼固定可靠,可保留髋臼的骨量。     

Survival and Clinical Outcomes at 30 to 35 Years Following Primary Total Hip Arthroplasty With a Cementless Femoral Stem Fully Coated With Hydroxyapatite

BackgroundThe purpose of the present study was to update and report clinical outcomes and survival of primary total hip arthroplasty using a cementless double-tapered titanium fully hydroxyapatite-coated stem at a follow-up > 30 years.MethodsThe outcomes of this series of 347 primary total hip arthroplasties were already published at a follow-up > 25 years, during which only 12 stems were revised. Since then, there were two additional stem revisions, bringing the total to 14 stem revisions (all of which also required cup revision). Patients still living with the original stem were assessed using the modified Harris Hip Score and patient satisfaction (very satisfied, satisfied, dissatisfied, and very dissatisfied). Revision incidence was calculated using the Kaplan-Meier (KM) method and Cumulative Incidence Function (CIF) at 35 years.ResultsAt a mean follow-up of 33 years (range, 31 to 35 years), 32 patients (34 hips) were still living with the original stem. Their mean modified Harris Hip Score was 86 points (range, 46 to 100) and all patients (100%) were very satisfied or satisfied with surgery. The revision incidence at 35 years considering (a) stem revision for any reason was 9.5% using KM and 4.5% using CIF; (b) stem revision for aseptic loosening was 3.1% using KM and 2.1% using CIF; and (c) reoperation or revision of any component for any reason was 45.3% using KM and 26.3% using CIF.ConclusionThe present study has demonstrated excellent survival at 35 years for a cementless double-tapered titanium fully hydroxyapatite-coated stem.Level of EvidenceLevel IV, Retrospective cohort study.     

人工全髋关节置换在骨性强直髋治疗中的临床及放射学评估

目的:对人工全髋关节置换(THA)在骨性强直髋治疗中的临床及放射学效果进行评估。方法:自2003年1月至2009年8月,20例(30髋)骨性强直的髋关节患者采用THA治疗,其中男12例,女8例;平均年龄36岁。术后临床随访根据Harris评分、患者疼痛缓解满意度、肢体长度差异、髋关节活动范围以及髋关节外展肌力进行评价。X线影像学随访包括对髋臼及股骨柄假体周围骨溶解、假体松动、透光线及异位骨化进行评价。术后平均随访时间为4年。结果:Harris评分由术前的平均(40.75±6.52)分提高至术后平均(86.40±5.42)分;邻近受累关节疼痛完全缓解13例,部分缓解7例;13例外展肌力量恢复满意,跛行症状明显缓解,肢体短缩下降至小于0.5cm;髋关节活动范围较术前显著改善。放射学评估发现2例髋关节周围异位骨化,1例股骨假体周围透光线,无关节假体脱位及翻修的病例。结论:近期随访发现THA在治疗骨性强直的髋关节中可以获得满意的临床疗效,矫正髋关节畸形,恢复髋关节功能,减轻患髋邻近关节的疼痛,改善患者的生活质量。     

Dual-mobility cups in revision acetabular reconstructions: Short-term outcomes in high-risk patients for instability

ObjectiveThe aim of this study was to evaluate the performance of dual-mobility (DM) cup systems for revision total hip arthroplasty (rTHA) in patients who had high risk for instability.MethodsWe prospectively followed up 34 hips of 30 patients (27 females, 3 males; mean age: 66.1 (range: 33 to 89) years) who underwent rTHA with DM cups for aseptic loosening in 23 hips, infection treatment as second or single stage in nine hips, and instability in two hips. Clinical functions of the patients were evaluated using the Harris Hip Score (HHS), and radiological migration or loosening of the DM cups were recorded. The survival of the components was calculated with the Kaplan-Meier survival analysis and failure was defined as any dislocation of the polyethylene (PE) insert, intraprosthetic dislocation (IPD), aseptic loosening of any component or total hip system revision due to any reason.ResultsThe mean duration of follow-up was 3.52 (range: 2.05 to 6.26) years. There was one dislocation of PE insert (2.9%), which was treated with closed reduction. There were two (5.8%) re-revisions for cemented DM cup due to migration. There was one PE insert and head change due to subacute infection. The mean HHS increased from 42.8 ± 6.7 (range: 34 to 60) points preoperatively to 87.3 ± 5.8 (range: 75 to 98) points postoperatively. The cumulative survival rate of the DM cup system was 91.2% (95% CI: 81.6–100%) with any revision, 94.1% (95% CI: 86.2–100%) with aseptic loosening and %97.1 (%95 CI: 91.4–100%) with dislocation as the end point at 3.5 years.ConclusionDual-mobility cups may provide good stability and represent a good option for revision acetabular reconstruction in patients who have high risk for instability.Level of evidenceLevel IV, therapeutic study.