Complex Revision Total Hip Arthroplasty Research Articles

Highly Porous Acetabular Cup and Augment Constructs in Complex Revision Total Hip Arthroplasty: What Predicts 10-Year Implant Survivorship?

BackgroundPorous tantalum acetabular cup and augment constructs have demonstrated favorable outcomes up to 5 years postsurgery despite severe bone loss during revision total hip arthroplasty (THA). Prior literature lacks long-term studies with substantial case numbers. This study aims to assess long-term clinical and radiographic outcomes 10 years postsurgery in patients undergoing revision THA with porous tantalum acetabular cup-augment constructs and determine factors associated with long-term survivorship. MethodsBetween 2000 and 2012, 157 revision THAs were performed in cases with major acetabular defects (mainly Paprosky type IIIA and IIIB) utilizing porous tantalum cup-augment constructs. Pelvic discontinuity was noted intraoperatively in 17 hips (11%). Postoperative radiographs were evaluated at regular intervals for implant stability and radiolucent lines. There were 49 patients who had complete radiographic follow-up at 10 years or longer postsurgery. ResultsThe 10-year survivorship free of revision of the cup-augment construct for aseptic loosening was 93%, free of any acetabular construct revision was 91%, free of any hip rerevision was 77%, and free of any reoperation was 75%. Pelvic discontinuity was associated with increased risk of reoperation (hazard ratio [HR] = 2.8), any hip rerevision (HR = 3.2), any cup-augment construct revision (HR = 11.8), and aseptic construct revision (HR = 10.0). Of unrevised cases with radiographs at 10 years, 4 hips showed radiographic loosening. Mean Harris hip scores improved from 47 preoperatively to 79 at 10 years. ConclusionsPorous tantalum acetabular cup-augment constructs used in revision THA with severe acetabular bone loss provide excellent implant survivorship at 10 years when the acetabulum is intact. Due to lower survivorship of cup-augment constructs in cases of pelvic discontinuity, additional construct fixation or stabilization methods are recommended, when a discontinuity is present. Level of EvidenceIV

Cemented dual-mobility constructs in uncemented revision acetabular components.

Dislocation remains a leading cause of failure following revision total hip arthroplasty (THA). While dual-mobility (DM) bearings have been shown to mitigate this risk, options are limited when retaining or implanting an uncemented shell without modular DM options. In these circumstances, a monoblock DM cup, designed for cementing, can be cemented into an uncemented acetabular shell. The goal of this study was to describe the implant survival, complications, and radiological outcomes of this construct. We identified 64 patients (65 hips) who had a single-design cemented DM cup cemented into an uncemented acetabular shell during revision THA between 2018 and 2020 at our institution. Cups were cemented into either uncemented cups designed for liner cementing (n = 48; 74%) or retained (n = 17; 26%) acetabular components. Median outer head diameter was 42 mm. Mean age was 69 years (SD 11), mean BMI was 32 kg/m2 (SD 8), and 52% (n = 34) were female. Survival was assessed using Kaplan-Meier methods. Mean follow-up was two years (SD 0.97). There were nine cemented DM cup revisions: three for periprosthetic joint infection, three for acetabular aseptic loosening from bone, two for dislocation, and one for a broken cup-cage construct. The two-year survivals free of aseptic DM revision and dislocation were both 92%. There were five postoperative dislocations, all in patients with prior dislocation or abductor deficiency. On radiological review, the DM cup remained well-fixed at the cemented interface in all but one case. While dislocation was not eliminated in this series of complex revision THAs, this technique allowed for maximization of femoral head diameter and optimization of effective acetabular component position during cementing. Of note, there was only one failure at the cemented interface.

Tapered Modular Femoral Stems for Revision Total Hip Arthroplasty Show Excellent Mid-Term Survivorship.

Revision total hip arthroplasty (THA) can be challenging in the face of proximal femoral bone loss, catastrophic implant failure, or recurrent hip instability. Tapered modular femoral stems have shown substantial success at short follow up for aseptic revisions. The purpose of this study was to report mid-term revision THA outcomes of a tapered modular femoral stem at a tertiary referral center used to treat both aseptic as well as periprosthetic joint infections (PJIs). We specifically sought to assess: (1) revision-free implant survivorship; (2) patient-reported outcome measurements (i.e., Hip Disability and Osteoarthritis Outcome Score, Joint Replacement [HOOS JR]); (3) postoperative surgical complications and 30-day readmissions; as well as (4) radiographic outcomes. We reviewed a consecutive series of 92 patients who underwent revision THA between 2009 and 2013 with a tapered modular femoral stem. After accounting for mortality (n=7) and loss to follow up (n=13), a total of 72 implants in 66 patients who had eight years of mean follow up (range, 2 to 11) were included. PJI (46%) was the predominant preoperative indication for revision THA, followed by aseptic loosening (25%), periprosthetic fracture (18%), and symptomatic hardware (10%). Outcomes of interest included all-cause revision-free survivorship, postoperative complications, and HOOS JR, as well as SF-12 scores. Radiographically, they were evaluated for subsidence, radiolucencies, and loosening. Aseptic revision-free survivorship of the femoral component was 95.8% (69 out of 72). Including septic cases, revision-free survivorship was 87.5% (63 cases), and 60 implants (83.3%) had an all-cause revision-free survivorship. For those patients who underwent septic revisions, eight out of nine remained infection free, while one underwent a resection arthroplasty. Furthermore, the cause for femoral aseptic revisions were subsidence (1.4%) and aseptic loosening (2.8%). Functional score improvements for HOOS JR, SF-12 PCS, as well as MCS were 29, 13, and 2, respectively (all p<0.001). There were eight emergency department visits (11.1%,) and six inpatient readmissions (8.3%). Additionally, two patients had dislocations (2.8%, two out of 72) not requiring revision. There were two cases of femoral subsidence and one aseptic loosening requiring revision; whereas, the rest did not demonstrate any progressive radiographic lucencies. The eight-year mean survivorship results of the tapered modular femoral stems in revision THA demonstrated excellent results. Our series found improved outcome scores and relatively low postoperative complications, which indicate a favorable implant survivorship profile for revision THA. These results serve to inform arthroplasty surgeons of expected outcomes of the modular stems when used for patients who need complex revision THA.

Midterm Outcomes of a Monoblock Dual-Mobility Cup Cemented into a Fully Porous Acetabular Component in Revision Total Hip Arthroplasty

AbstractUtilization of dual-mobility (DM) constructs has been a promising management option to address the risk of hip instability after complex revision total hip arthroplasty (rTHA). The aim of this study is to report a minimum 2-year outcome and survivorship of a monoblock DM cup cemented in a fully porous acetabular shell in complex acetabular rTHA cases. A retrospective review of 76 patients who underwent rTHA with a novel construct that utilized an inner DM cup cemented into a fully porous outer acetabular metal shell was conducted. Demographics, radiographic, and clinical outcomes such as readmissions, dislocation, and revisions were collected. Survivorship was analyzed by the Kaplan–Meier (KM) method. Thirty cases with a minimum of 2-year follow-up were included. Patients were, on average, 65.17 ± 10.26 years old with a mean body mass index of 28.55 ± 6.33 kg/m2. Seven patients (23.3%) required reoperations. Four patients underwent acetabular revision (periprosthetic joint infection: n = 2 [6.7%]; dislocation: n = 1 [3.3%]; aseptic loosening [fully porous cup]: n = 1[3.3%]). Three patients underwent reoperation without acetabular implant revision (debridement, antibiotics, and implant retention for prosthetic joint infection: n = 2 [6.7%]; femoral periprosthetic fracture: n = 1 [3.3%]). KM survivorship analysis of all-cause acetabular revision showed survival rates of 96.7% at 6 months, 93.3% at 1 year, and 89.7% at 2 years. KM survivorship of aseptic acetabular revision showed rates of 96.7% at 1 year and 92.9% at 2 years. KM analysis of acetabular cup fixation showed rates of 100% at 1 year and 96.2% at 2 years. The rate of dislocation in our cohort was 3.3% (1 out of 30). The use of a DM acetabular cup cemented into a fully porous acetabular revision shell in complex rTHA cases has a low risk of instability and loosening at 2 years with excellent mid-term implant survivorship. The use of this construct is a good option in patients with complex acetabular reconstruction and an elevated risk for instability. This was a retrospective cohort study with a level III evidence.

The application of custom-made 3D-printed titanium augments designed through surgical simulation for severe bone defects in complex revision total hip arthroplasty

BackgroundWith the development of radiology and three-dimensional (3D) printing technology, custom-made 3D-printed titanium augments have been more widely used. However, the radiological and clinical outcomes of custom-made augments lack reports. To better understand the clinical effect of using 3D-printed titanium augments and the significance of accurate placement, the aim of this study was to assess the outcomes when using custom-made 3D-printed titanium augments and to validate the idea that surgical simulation should be done before designing custom-made augments.MethodsA retrospective review was conducted on 31 surgical simulations and revision total hip arthroplasties using custom-made 3D-printed titanium augments. The safe zone, cup position, and hip rotation center were measured on anteroposterior radiographs. Clinical outcomes were assessed with a mean 21.1 months of follow-up.ResultsAll patients were positioned within the safe zone, and none of the acetabular cups nor the custom-made augments had any evidence of migration at the latest follow-up. A strong correlation was found between the planned cup position and the postoperative position. The average vertical position of the center of rotation was significantly increased from 3.55 cm to 2.35 cm. The mean Harris Hip Score was increased from 40.81 preoperatively to 65.46 postoperatively. Complications included gait abnormality, groin pain, fracture of the greater trochanter, and partial palsy of the sciatic nerve. However, patient satisfaction reached 92.3%.ConclusionSurgical simulations help to design custom-made augments accurately and improve surgical plans. Acetabular components supported with custom-made 3D-printed augments is a useful method to bridge severe bone deficiencies. In this study, both the radiologic results and clinical outcomes were favorable.Level of evidenceLevel 4.

What is the failure rate of constrained liners in complex revision total hip arthroplasty?

Recurrent hip dislocation after multiple revision total hip arthroplasty is a severe complication. Therefore, constrained acetabular liners (CL) have been used during salvage procedures. We report our experience of constrained liners in a re-revision setting with focus on re-dislocation. We also evaluated acetabular and femoral bone loss as potential risk factor. Between January 2013 and December 2016, 65 patients were treated in a single institution for revision and re-revision hip arthroplasty using CL. The indication for using a CL was a high risk of re-redislocation after multiple recurrent hip dislocation including failed Dual Mobility Cups (DMC). Compromising soft tissue defects as well as severe bone defect were therefore regarded as high risks. Thirty-eight patients (77.6%) underwent a minimum of three surgical procedures before the index revision procedure. Sixteen patients (24.6%) were excluded as they were lost to follow-up, expired before minimum follow-up or refused study participation, leaving 49 patients in the analysis (75.4%). The mean follow-up was 62months (44-74; SD = 7.7). We assessed the following potential risk factors for revision or dislocation: type of surgical setting (septic/aseptic), BMI, cup inclination angle, size of liner used and acetabular and femoral bone loss according to Paprosky classification. The primary endpoints were dislocation or repeat revision for any reason. Of the 49 patients, we found an overall re-revision rate of 40.8% (20/49) and a dislocation rate of 30.6% (15/49). There were no significant differences among the surgical re-revision rate or dislocation rate as a factor of patient characteristics. In terms of bone loss, there was a trend towards higher revision rates for increasing acetabular and femoral bone loss, but without statistical significance. We found the use of a constrained liner in a re-revision setting still bears a high risk of re-revision and re-dislocation. Therefore we restrained from using constrained liners in favour of Dual mobility cups. In this study there was no significant higher dislocation rate in the subgroup of periprosthetic infection. Furthermore the rigid design of a constrained liner bears the known risk of structural failure of acetabular reconstruction implants. Severe acetabular or femoral bone defects seem to have an impact on the revision rate, but not on the dislocation rate with regards to the restored offset and center of the hip. Results have to be taken into context such that the study population inherently has a predisposition for poorer outcomes. Indications should be strongly filtered for patients at high risk for recurrent hip joint dislocation including failed DMCs with only limited bone loss and moderate soft tissue defects. Our modification to the existing classification with a high inter and intraobserver reliability will make future studies more comparable regarding revisions and bone stock loss. Still furtherresearch using objective and reproducible parameters is needed to better analyze data especially in the background of complex revision hip arthroplasty.

Tripolar Constrained and Dual Mobility Liners Are Both Successful When Cemented Into Tantalum Acetabular Revision Shells in Complex Revision Total Hip Arthroplasty

BackgroundInstability is a common complication after revision total hip arthroplasty. Tripolar constrained (TC) and dual mobility (DM) liners cemented into tantalum acetabular revision (TM) shells are established alternatives that reduce instability risk. This study compares outcomes of TC and DM liners cemented into TM shells in complex revision hip replacements.MethodsFifty cases using a TM shell and a TC or DM cemented liner with at least 12 months of follow-up were identified. There were 25 TC and 25 DM liners. Clinical, radiographic, and patient-reported outcomes were collected. Reasons for re-revision and failures were analyzed.ResultsThe average age was 73 years in the TC group and 75 years in the DM group. The median follow-up duration was 50 months (23 - 96) and 13 months (12 – 21) for the TC and DM groups, respectively. The mean Harris Hip Score improved from 37 to 61 for the TC group and from 51 to 73 in the DM group at the last review. Two TC cases required revision for wear and liner failure. One DM insert was changed at reoperation for periprosthetic femur fracture. There were no failures of cement fixation in either group and no revisions for cup loosening.ConclusionsIn complex revision hip replacement with a history of instability or judged to have a high risk of instability postoperatively, TC and DM liners cemented into tantalum revision shells are both successful, giving acceptable results. The improved arc of movement with DM liners, minimizing impingement, makes them preferable except when there is a global abductor deficiency or severe joint laxity.

Low Revision Rates at More Than 10 Years for Dual-Mobility Cups Cemented Into Cages in Complex Revision Total Hip Arthroplasty

BackgroundInstability and aseptic loosening are the two main complications after revision total hip arthroplasty (rTHA). Dual-mobility (DM) cups were shown to counteract implant instability during rTHA. To our knowledge, no study evaluated the 10-year outcomes of rTHA using DM cups, cemented into a metal reinforcement ring, in cases of severe acetabular bone loss. We hypothesized that using a DM cup cemented into a metal ring is a reliable technique for rTHA at 10 years, with few revisions for acetabular loosening and/or instability. MethodsThis is a retrospective study of 77 rTHA cases with severe acetabular bone loss (Paprosky ≥ 2C) treated exclusively with a DM cup (NOVAE STICK; Serf, Décines-Charpieu, France) cemented into a cage (Kerboull cross, Burch-Schneider, or ARM rings). Clinical scores and radiological assessments were performed preoperatively and at the last follow-up. The main endpoints were revision surgery for aseptic loosening or recurring dislocation. ResultsWith a mean follow-up of 10.7 years [2.1-16.2], 3 patients were reoperated because of aseptic acetabular loosening (3.9%) at 9.6 years [7-12]. Seven patients (9.45%) dislocated their hip implant, only 1 suffered from chronic instability (1.3%). Cup survivorship was 96.1% at 10 years. No sign of progressive radiolucent lines were found and bone graft integration was satisfactory for 91% of the patients. ConclusionThe use of a DM cup cemented into a metal ring during rTHA with complex acetabular bone loss was associated with low revision rates for either acetabular loosening or chronic instability at 10 years.

Survivorship of the Modular Femoral Revision Stem

The geriatric population represents a rapidly growing segment of society with prolonged life expectancies and more active lifestyles. Many of these patients have already undergone primary total hip arthroplasty (THA) and are presenting with aseptic loosening, polyethylene wear, osteolysis, or periprosthetic fractures. Therefore, the demand for hip revision procedures is expected to grow. Currently, there are many modular implant options available for use in complicated revision THA. Early results of modular femoral revision systems are promising for the treatment of the deficient femur in complex revision THA. The objective of this study was to evaluate component survivorship of a modular femoral revision system in revision THA. A retrospective review was conducted using electronic health records of patients who underwent revision THA performed by 1 of 3 surgeon investigators from 2010 through 2014. The authors included all patients who underwent a revision THA using a specific modular femoral revision system. The authors evaluated component survivorship and time to re-revision THA. Fifty-one revision THAs were included. Seven patients required a second revision THA (13.7%; 95% confidence interval, 4%-23%). Mean time to re-revision THA was 4.88±3.9 months. Kaplan-Meier survivorship using re-revision for any reason was 86.3% at 60 months. This study showed excellent component survivorship of the specific modular femoral revision system in revision THA. [Orthopedics. 2019; 42(5):294-298.].

Revision Total Hip Arthroplasty With a Monoblock Splined Tapered Grit-Blasted Titanium Stem

BackgroundIn revision total hip arthroplasty (THA), proximal femoral bone loss creates a challenge of achieving adequate stem fixation. The purpose of this study was to examine the outcomes of a monoblock, splined, tapered femoral stem in revision THA. MethodsOutcomes of revision THA using a nonmodular, splined, tapered femoral stem from a single surgeon were reviewed. With a minimum of 2-year follow-up, there were 68 cases (67 patients). Paprosky classification was 3A or greater in 85% of the cases. Preoperative and postoperative Harris Hip Scores (HHS), radiographic subsidence and osseointegration, limb length discrepancy, complications, and reoperations were analyzed. ResultsThe Harris Hip Score improved from 37.4 ± SD 19.4 preoperatively to 64.6 ± SD 21.8 at final follow-up (P < .001). There were 16 revision procedures—8 for septic indications and 8 for aseptic indications. Subsidence occurred at a rate of 3.0% and dislocation at 7.4%. Limb length discrepancy of more than 1 cm after revision was noted in 13.6% of patients. Bone ingrowth was observed in all but 4 patients (94.1%). At 4-year follow-up, Kaplan-Meier estimated survival was 72.9% (95% confidence interval [CI] 57.0-83.8) for all causes of revision, 86.6% (95% CI 72.0-93.9) for all aseptic revision, and 95.5% (95% CI 86.8-98.5) for aseptic femoral revision. ConclusionAlthough complications were significant, revision for femoral aseptic loosening occurred in only 3 patients. Given the ability of this monoblock splined tapered stem to adequately provide fixation during complex revision THA, it remains a viable option in the setting of substantial femoral bone defects.

Minimum Five-Year Outcomes with Porous Tantalum Acetabular Cup and Augment Construct in Complex Revision Total Hip Arthroplasty.

The use of a trabecular metal revision shell with metal augmentation to fill segmental or irregular defects during complex revision hip arthroplasty has been shown to provide good short-term results in prior published series. Longer-term results of the several cup-augment constructs used clinically are not known. The objective of this study was to report, with minimum 5-year radiographic and clinical follow-up, the outcome of these various constructs in revision total hip arthroplasty. Eighty-four patients (85 hips) underwent revision total hip arthroplasty with use of porous tantalum augments between 2000 and 2007 at a single institution and were retrospectively reviewed. Fifty-seven of the patients (58 hips) had clinical and radiographic follow-up at a minimum of 5 years. At the time of revision, the majority of the hips had acetabular defects classified as Paprosky Type 3A (28 of 58, 48%) or Type 3B (22 of 58, 38%). Eleven (19%) of the hips also had preoperative pelvic discontinuity. All hips were assessed clinically at a minimum of 5 years with use of the Mayo hip score. Postoperative radiographs were reviewed for implant stability, the presence and location of radiolucent lines and healing of the discontinuity if present. In 2 (3%) of the 58 hips, the constructs failed because of aseptic loosening of the acetabular component and re-revision was indicated. Six (10%) of the 58 hips demonstrated a radiolucent line between the trabecular metal shell and bone in DeLee and Charnley zone 3. In 1 hip that underwent re-revision and in 5 of the 6 hips with a zone-3 radiolucency, a pelvic discontinuity was present at the time of the index revision. The mean preoperative Mayo hip score was 35.7, which improved to 61.9 at 3 months and was 61.7 at the minimum 5-year follow-up. With failure defined as aseptic loosening requiring repeat revision surgery, this cohort demonstrated 97% survivorship and maintained satisfactory hip function at the minimum 5 years after the index revision surgery. Six of the 11 hips with preoperative pelvic discontinuity either failed or developed a radiolucency in zone 3 and are considered at risk for future revision. Pelvic discontinuity should prompt consideration of the addition of adjunctive fixation or the use of alternative techniques. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Gluteus Maximus Advancement Flap Procedure for Reconstruction of Posterior Soft Tissue Deficiency in Revision Total Hip Arthroplasty

The current study describes the surgical technique and early outcomes of a gluteus maximus advancement flap procedure for the treatment of posterior soft tissue insufficiency among patients with complex revision total hip arthroplasty. This retrospective case series was conducted with a prospective, single-institution arthroplasty registry. Patients who underwent a gluteus maximus advancement flap procedure in the setting of revision total hip arthroplasty between January 2012 and January 2016 were eligible for inclusion (N=7). Primary indications for the gluteus maximus flap procedure included periprosthetic infection with persistent wound breakdown (n=4), persistent symptomatic aseptic pseudotumor in the setting of adverse local tissue reaction after unsuccessful operative debridement (n=2), and abductor insufficiency with recurrent hip instability after unsuccessful placement of a constrained liner (n=1). All patients who underwent a gluteus maximus advancement flap procedure for chronic periprosthetic infection or adverse local tissue reaction had healing of the wound and were infection-free at the last follow-up. In the early postoperative period, 2 patients had recurrent wound infection that required flap elevation. The patients remained infection-free after the subsequent procedure. No patient had repeat instability, and no complications of flap necrosis or nerve palsy occurred. The gluteus maximus advancement flap procedure provides a diverse range of soft tissue coverage options for patients with recalcitrant periprosthetic joint infection, adverse local tissue reaction with pseudotumor, or recurrent instability. [Orthopedics. 2017; 40(3):e495-e500.].

In Vivo Dissociation Of A Dual Articulation Bearing In Revision THA - Case Report

Revision total hip arthroplasty (THA) can be a difficult reconstructive procedure that challenges the skills of even the adroit orthopaedic surgeon. Revision THA for aseptic failure after acetabular/pelvic fracture is one of the more difficult challenges in the realm of hip reconstruction. The high complication rate associated with this complex reconstruction remains the dominant obstacle for obtaining consistent satisfactory outcomes. The specific problems of boney defects, pelvic malalignment, heterotopic ossification, soft tissue scarring, and muscle atrophy compromise the goals of revision THA, which include osteointegration of implant to host bone, restoration of hip joint biomechanics, and joint stability12. Recurrent dislocation in revision THA is one of the more frustrating complications for both the patient and the surgeon, and it remains so even today. Despite this, there continues to be developments in surgical technique and prosthetic design to enhance prosthetic hip stability. One prosthetic design, the dual articulation hip bearing, was developed to enhance THA stability. The dual articulation concept was developed by professor Gilles Bousquet and engineer André Rambert in the late 1970’s14. The dual mobility design incorporates two articular surfaces within the THA bearing. The acetabular cup is composed of a metallic bearing that articulates with an ultra high molecular weight polyethylene (UHMWPE) ball. Within the UHMWPE head is an inner ball that is enclosed within the polyethylene (figure 1). This design concept increases hip primary arc range before impingement.The Bousquet dual mobility concept has been used over the last 20 years in Europe with successful clinical outcomes6,7,9,11. In the United States, the dual articulation bearing design received FDA clearance in 2011. However, as with the addition of any modular part, there is the potential for new in-vivo failure mechanisms. With the dual mobility construct, the new failure mechanism is dissociation of the inner head1,10. We report in this case an early traumatic dissociation of a dual mobility bearing utilized in a complex revision THA. To our knowledge, this is the first reported case of a traumatic in-vivo disassembly of a dual articulation bearing THA.Key Words: Dual Articulation, Dual Mobility, Active Articulation, THA, Revision, Dissociation, Dislocation

Durable Fixation With a Modern Fully Hydroxylapatite-Coated Long Stem in Complex Revision Total Hip Arthroplasty

We describe the use of a fully hydroxylapatite-coated long-stem femoral implant in a series of 40 complex revision total hip arthroplasties. All reconstructions involved severe bone loss or malalignment and were accomplished entirely without the use of augmentary bone graft. Outcomes were evaluated at 7 minimum years of follow-up (average, 10.2 years). Three stems were rerevised because of infection, trauma, and loosening with nonunion of a fracture. Bone ingrowth was radiographically evident by one postoperative year in all other cases. There were no cases of subsidence. Stress shielding with thigh pain was seen in one patient. The stem provided immediate stability and excellent long-term fixation in these reconstructions of severely diseased femurs.

Complex Revision Total Hip Arthroplasty with Modular Stems at a Mean of 14 Years

We retrospectively reviewed 87 patients (92 hips) who had revision hip surgery to determine whether a proximally coated, modular femoral component would remain stably fixed at long-term followup. Thirteen patients died and 12 patients were lost to followup leaving 62 patients (67 hips) available for review with minimum followup of 8 years (mean, 14 years; range, 8-17 years). Preoperative radiographs were reviewed using Paprosky's classification. Postoperative radiographs were reviewed for osteolysis, endosteal hypertrophy, cortical hypertrophy, distal pedestals, component breakage, and loosening. Thirty-seven hips underwent femoral allografting, 10 of which were proximal femurs. With revision as the endpoint the Kaplan-Meier survivorship (including deaths and loss to followup) was 60% at 14 years. Forty-seven of the 57 (82%) noncemented stems were bone ingrown. All had relative proximal bone preservation and 33 of 57 (58%) had bone hypertrophy in the diaphysis around zones 2 and 6. There were five aseptic failures (9%). Each of those was Paprosky Class IIIB or IV preoperatively. There were no long-term failures in Paprosky Class II or IIIA. The aseptic failures have been re-revised. This modular stem resulted in reliable fixation with relative preservation of proximal bone stock at this intermediate interval in complex revisions in Paprosky Class II and IIIA. Paprosky Class IIIB and IV defects may need additional component fixation options.

The Extended Trochanteric Osteotomythrough the Lateral Approachin Revision Hip Arthroplasty

Purpose : To review the results and discuss the technique for an extended trochanteric osteotomy through the lateral approach in revision total hip arthroplasty. Materials and Methods: Twenty patients were reviewed after an average follow-up of 30.4 months (range, 24-56 months) between 1999 and 2003. The indications for the extended trochanteric osteotomy included the removal of a well-fixed cemented or cementless stem in 12 hips, varus remodeling of the femur in 3 hips and trochanteric malposition in 5 hips. The length of the osteotomy, the proximal migration of the osteotomized fragment, the fixation status of the femoral stem, the union status of the osteotomy site and complications were evaluated at the last follow-up. Results : The mean length of the osteotomy was 12 cm (range, 8-20 cm). Radiographic union of the osteotomy site was noted in all cases after an average of 3.8 months (range, 2.5-6.0 months). The mean migration of the osteotomized fragment was 2.4 mm (range, 0-8 mm). The complications included postoperative dislocation in 3 hips and fractures of the osteotomy fragment in 2 hips, which were treated at the last follow up. Fixation of the stem with bone ingrowth was noted in all patients. Conclusion : An extended trochanteric osteotomy through the lateral approach can be performed safely in complex revision total hip arthroplasty.

Constrained Acetabular Components in Complex Revision Total Hip Arthroplasty

We retrospectively reviewed 39 consecutive hips in 38 patients to examine the outcome of acetabular fixation and stability in patients with the tripolar constrained acetabular component who had complex revision surgery at 2 to 5 years of followup. Preoperative indications included recurrent dislocation, loose acetabular component with instability, migrated bipolar, resection arthroplasty conversions, and primary arthroplasty. Postoperative radiographs were reviewed for radiolucencies, loosening, migration, or breakage. The patients' average age was 65 years (range, 44-83 years). Thirty-five of the 39 acetabular components (91%) are well fixed and bony ingrown. There were no dislocations. One patient was involved in an motor vehicle accident 1 year postoperatively and sustained a fracture of the ilium and a 2 mm radiolucency about the component which is now stable. Three patients had acetabular revisions. Two patients were revised to a tripolar cemented into a cage and are doing well. The tripolar constrained acetabular component offers reliable fixation and joint stability in patients at high risk for dislocation in this short term followup. Therapeutic study, Level IV (case series). See the Guidelines for Authors for s complete description of levels of evidence.

Reverse Skeletal Traction for Instability Following Revision Total Hip Arthroplasty

Dislocation is a recognized complication following total hip arthroplasty (THA). Immobilization of the hip has been used successfully to treat those cases due to soft-tissue laxity. In two patients who had severe instability of the hip following complex revision THA, skeletal traction through the tibia was applied in a cephalad direction for three weeks. This unique method of employing traction maintained a reduction and resulted in a stable hip at the six-month follow-up evaluation in both patients. Reverse skeletal traction is a valuable treatment option when more conventional methods of immobilization of the hip will not maintain a reduction due to soft-tissue compromise.