Previous work has demonstrated increased implant failure in patients with DDH compared to osteoarthritis with historic methods and implants. This study examines outcomes of modern total hip arthroplasty (THA) techniques using uncemented fixation and cross-linked PE (XLPE) bearings for DDH.

A consecutive series of 879 patients with DDH who underwent primary THA with uncemented components and a XLPE bearing at a single institution between 1999 and 2016 were identified. Mean age at index arthroplasty was 51 years, with 78% females. Mean follow-up was 8 years.

5- and 10-year survivorships free of revision were 98.4% and 98%, respectively. 5- and 10-year survivorships free of reoperation for any reason were 97% and 96%, respectively. Survivorship free of acetabular revision for aseptic loosening was 99.8% at 5 and 10 years, while survivorships free of femoral revision for aseptic loosening were 99.7% at 5 years and 99.5% at 10 years. Survivorship free of reoperation for PE damage (2 liner fractures, 2 rim damage from impingement) was 99.3% at 10 years. There were no revisions for bearing surface wear or osteolysis. 13% of patients experienced complications (4% dislocation, 3.3% wound complication rate). Ten-year survivorship free of reoperation for instability was 99.2%. 8 patients developed infection requiring operation (<1%). 100 patients had a prior pelvic osteotomy (11%), which did not increase rate of complications (p=0.22) or reoperations (p=0.51).

Fixation with modern uncemented implants has dramatically reduced implant loosening in patients with DDH, and the use of XLPE bearings has markedly reduced revision for PE wear/osteolysis in this young patient population, leading to dramatically improved mid/long-term survivorship compared to historic series.

Advantages of cones in revision TKA

Reliable, Durable, Easy to do, Solves major problems (bone loss, fixation)

Assess union rate, complications, and outcomes of large series of contemporary extended trochanteric osteotomies (ETOs) performed during revision THAs.

From 2003 to 2013, 612 ETOs were performed during revision THAs using 2 techniques. 367 were Paprosky type and 245 were Wagner type. Indications were aseptic loosening (65%), periprosthetic joint infection (18%), periprosthetic fracture (6%), femoral implant fracture (5%), and other (6%). Mean age 69 years, 58% male. Median follow-up 5 years (range, 2.1 to 13 years).

Mean Harris Hip Scores increased from 57 preoperatively to 77 at latest follow-up (p=0.0001). Radiographic union of the extended osteotomy occurred in 98%. There were 9 ETO nonunions. Mean time to union of the distal transverse osteotomy was 5.9 months (range, 1 month − 2 years). Mean trochanteric osteotomy fragment migration prior to union was 3 mm (range, 0–29 mm). Over 1 cm of migration occurred in 7.4%. Intraoperative fracture of the ETO diaphyseal fragment occurred in 4%, and postoperative greater trochanter fractures in 8.8%. Other complications: dislocation in 5.7% and infection in 3.4%. Dislocation occurred in 19 of 462 with ETO migration < 1 cm and 4 of 39 with ETO migration ≥1 cm (p=0.08). Ten year survivorship free of revision for aseptic femoral loosening, free of any component removal or revision, and free of reoperation were 97%, 91%, and 82%, respectively.

The union rate after ETO was high and notable trochanteric migration was infrequent. The most common complication was fracture intraoperatively or postoperatively of the osteotomy fragment.

The majority of patients who develop hip arthritis have a mechanical abnormality of the joint. The structural abnormalities range from instability (DDH) to impingement. Impingement leads to osteoarthritis by chronic damage to the acetabular labrum and adjacent cartilage.

In situations of end-stage secondary DJD, hip arthroplasty is the most reliable treatment choice. In young patients with viable articular cartilage, joint salvage is indicated. Treatment should be directed at resolving the structural abnormalities that create the impingement.

Femoral abnormalities corrected by osteotomy or increased head-neck offset by chondro-osteoplasty creating a satisfactory head-neck offset. This can safely be done via anterior surgical dislocation. The acetabular-labral lesions can be debrided and/or repaired. Acetabular abnormalities should be corrected by “reverse” PAO in those with acetabular retroversion or anterior acetabular debridement in those with satisfactory posterior coverage and a damaged anterior rim.

Often combinations of the above are indicated.

There are pros and cons of all bearing surface options for our young patients. I pick the bearing surface for my young patients trying to maximise durability and minimise risks.

For the ultra-young, ≤30 years of age patient, I use ceramic-on-ceramic. The pros of this are the best wear couple available and a favorable track record (with well designed implants). The risks can be minimised: fracture risk now decreased, runaway wear minimised with good surgical technique, impingement problems minimised with good technique and well designed implants, as well as squeaking is minimised with good design (majority of reported squeakers are of one designed socket).

I don't use metal-on-metal because I am not willing to subject young patients to potentially 50+ years of high metal ion exposure.

I also don't use HCLPE. This would be okay from a biologic standpoint but I still have concerns about long-term wear durability. So the marked superior wear characteristics of ceramic-ceramic win in my view.

For my middle age patients, 30–60, I use HCLPE I don't use ceramic-ceramic because at some point between 30 and 60 years of age the improved wear properties are outweighed by their potential risks (fracture, impingement, squeak). HCLPE at short F/U (<15 years) appears to be durable, reliable with good wear properties so it is a reasonable choice. Using a ceramic head versus CoCr provides minimal improvement in wear properties in the lab but no marked advantage in vivo. Concerns persist about cobalt-chrome corrosion so I use ceramic heads in the majority of patients

For patients under age 60 the wear characteristics of HCLPE appear very favorable and one doesn't assume other risks seen in with metal-on-metal and ceramic-ceramic. Little justification for a hard-on-hard bearing in this patient subgroup. I use ceramic heads in majority to avoid corrosion issues.

Background

Total knee arthroplasty (TKA) overall is a very reliable, durable procedure. Biomechanical studies have suggested superior stress distribution in metal-backed tibial trays, however, these results have not been universally observed clinically. Currently, there is a paucity of information examining the survival and outcomes of all-polyethylene tibial components.

115 patients undergoing primary unilateral THA were randomized to either DAA or MPA. Groups did not differ in mean age, sex, or mean body mass index. Functional results included time to discontinue gait aids, discontinue all narcotics, and independence with various activities of daily living. Activity in study subjects was measured with 5 wearable activity monitoring sensors with tri-axial MEMS accelerometers and validated custom algorithms and conducted over three days at pre-op, 2 weeks, 8 weeks, and one year. SF-12, WOMAC, and HHS scores to one year were also tabulated.

Early functional recovery slightly favoured DAA compared to MPA; time to discontinue walker (10 vs. 14.5 days), time to discontinue all gait aids (17.3 vs 23.6 days), ascend stairs with gait aid (5.4 vs. 10.3 days), and to walk 6 blocks (20.5 vs. 26.0 days). There were no other differences in early functional milestones. Activity monitoring at two weeks postoperatively slightly favoured DAA; mean steps per day were 3897 versus MPA 2,235, percent of day active, DAA 10.5% versus MPA 6.9%. There was no difference in activity monitoring pre-operatively, at two months, or at one year. There was no difference at one year with the SF-12. There was no difference in the SF-12 mental component or the HOOS at any time point. There was no loosening or subsidence of any of the components in any hip.

Both the direct anterior and posterior approach provided excellent early postoperative recovery with a low complication rate. The direct anterior patients had slightly faster recovery than the mini-posterior approach patients, with slightly shorter times to achieve milestones of function and as measured by advanced, quantitative activity monitoring at 2 weeks postoperatively.

It has become clear that computer navigation in total joint replacement provides more reliable obtaining of a neutral mechanical axis during total knee surgery. The real issue is when one attains a more reliable mechanical axis, is that going to change the clinical outcome both in terms of function and durability? To date, we really haven't been able to answer that question definitively. Is there really a one simple target value for alignment in all patients undergoing total knee replacement?

The constraints on accuracy imposed by our standard total knee instruments and the constraints on assessment imposed by 2-dimensional radiographs made broad, simple targets like a mechanical axis ± 3 degrees reasonable starting points; yet we have not further worked to verify if we can do better. It is naïve to think that the complex motion at the knee occurring in 6 dimensions over time can be reduced to a single static target value like a neutral mechanical axis and have strong predictive value in regard to the success or failure of an individual TKA. We assessed 399 knees of 3 different modern cemented designs at 15 years and found that factors other than alignment were more important than alignment in determining the 15-year survival. That work does not mean that alignment is not important, instead it suggests that either the way we traditionally define malalignment (outside 0 ± 3 degrees) is too imprecise or that the other causes of failure overwhelm malalignment in determine TKA durability.

Background: Total knee arthroplasty (TKA) overall is a very reliable, durable procedure. Biomechanical studies have suggested superior stress distribution in metal-backed tibial trays, however, these results have not been universally observed clinically. Currently, there is a paucity of information examining the survival and outcomes of all-polyethylene tibial components.

Methods: We reviewed 31,939 patients undergoing a primary TKA over a 43-year period (1970–2013). There were 28,224 (88%) metal-backed and 3,715 (12%) all-polyethylene tibial components. The metal-backed and all-polyethylene groups had comparable demographics with respect to sex distribution (57% female for both) mean age (67 vs. 71 years), and mean BMI (31.6 vs. 31.1). Mean follow-up was 7 years (maximum 40 years).

Results: The purpose of this investigation was to analyze the outcomes of all-polyethylene compared to metal backed components in TKA and to determine (1) is there a difference in overall survival? All-polyethylene tibial components had improved survivorship (P<0.0001) and metal backed tibias were at increased risk of revision (HR 3.41, P<0.0001). (2) Does body mass index (BMI) or age have an affect on survival of all-polyethylene compared to metal-backed tibial components? All-polyethylene tibias had improved survival (P<0.01) in all ages groups except in patients 85 years or greater, where there was no difference (P=0.16). All-polyethylene tibial components had improved survival (P<0.005) for all BMI's except in the morbidly obese (BMI ≥40) where there was no difference (P=0.20). (3) Is there an increased risk of post-operative infection? Metal-backed tibial components were found to have an increased risk of infection (HR 1.60, P=0.003). (4) Is there a difference in the rate of reoperation and post-operative complications? Metal-backed tibial components were found to have an increased risk of reoperation (HR 1.84, P<0.0001).

Conclusions: The use of all-polyethylene tibias should be considered for the majority of patients, regardless of age and BMI.

Background: Structural hip deformities including developmental dysplasia of the hip (DDH) and femoroacetabular impingement (FAI) are thought to predispose patients to degenerative joint changes. However, the natural history of these malformations is not clearly delineated.

Methods: Seven-hundred twenty-two patients ≤55 years that received unilateral primary total hip arthroplasty (THA) from 1980–1989 were identified. Pre-operative radiographs were reviewed on the contralateral hip and only hips with Tönnis Grade 0 degenerative change that had minimum 10-year radiographic follow-up were included. Radiographic metrics in conjunction with the review of two experienced arthroplasty surgeons determined structural hip diagnosis as DDH, FAI, or normal morphology. Every available follow-up AP radiograph was reviewed to determine progression from Tönnis Grade 0–3 until the time of last follow-up or operative intervention with THA. Survivorship was analyzed by Kaplan-Meier methodology, hazard ratios, and multi-state modeling.

Results: One-hundred sixty-two patients met all eligibility criteria with the following structural diagnoses: 48 DDH, 74 FAI, and 40 normal. Mean age at the time of study inclusion was 47 years (range 18–55), with 56% females. Mean follow-up was 20 years (range 10 – 35 years). Thirty-five patients eventually required THA: 16 (33.3%) DDH, 13 (17.6%) FAI, 6 (15.0%) normal. Kaplan-Meier analysis demonstrated that patients with DDH progressed most rapidly, followed by FAI, with normal hips progressing the slowest. The mean number of years spent in each Tönnis stage by structural morphology was as follows: Tönnis 0: DDH = 17.0 years, FAI = 14.8 years, normal = 22.9 years; Tönnis 1: DDH = 12.2 years, FAI = 13.3 years, normal = 17.5 years; Tönnis 2: DDH = 6.0 years, FAI = 9.7 years, normal = 8.6 years; Tönnis 3: DDH = 1.6 years, FAI = 2.6 years, normal = 0.2 years.

Analysis of degenerative risk for categorical variables showed that patients with femoral head lateralization >10 mm, femoral head extrusion indices >0.25, acetabular depth-to-width index <0.38, lateral center-edge angle <25 degrees, and Tönnis angle >10 degrees all had a greater risk of progression from Tönnis 0 to Tönnis 3 or THA. Among patients with FAI morphology, femoral head extrusion indices >0.25, lateral center-edge angle <25 degrees, and Tönnis angle >10 degrees all increased the risk of early radiographic progression. Analysis of degenerative risk for continuous variables using smoothing splines showed that risk was increased for the following: femoral head lateralization >8 mm, femoral head extrusion index >0.20, acetabular depth-to-width index <0.30, lateral center-edge angle <25 degrees, and Tönnis angle >8 degrees.

Conclusions: This study defines the long-term natural history of DDH and FAI in comparison to structurally normal young hips with a presumably similar initial prognostic risk (Tönnis Grade 0 degenerative change and contralateral primary THA). In general, the fastest rates of degenerative change were observed in patients with DDH. Furthermore, risk of progression based on morphology and current Tönnis stage were defined, creating a new prognostic guide for surgeons. Lastly, radiographic parameters were identified that predicted more rapid degenerative change, both in continuous and categorical fashions, subclassified by hip morphology.

Background: Total knee arthroplasty (TKA) overall is a very reliable, durable procedure. Biomechanical studies have suggested superior stress distribution in metal-backed tibial trays, however, these results have not been universally observed clinically. Currently there is a paucity of information examining the survival and outcomes of all-polyethylene tibial components.

Methods: We reviewed 31,939 patients undergoing a primary TKA over a 43-year period (1970–2013). There were 28,224 (88%) metal-backed and 3,715 (12%) all-polyethylene tibial components. The metal-backed and all-polyethylene groups had comparable demographics with respect to sex distribution (57% female for both) mean age (67 vs. 71 years), and mean BMI (31.6 vs. 31.1). Mean follow-up was 7 years (maximum 40 years).

Results: The purpose of this investigation was to analyze the outcomes of all-polyethylene compared to metal-backed components in TKA and to determine (1) is there a difference in overall survival? All-polyethylene tibial components had improved survivorship (P<0.0001) and metal-backed tibias were at increased risk of revision (HR 3.41, P<0.0001). (2) Does body mass index (BMI) or age have an effect on survival of all-polyethylene compared to metal-backed tibial components? All-polyethylene tibias had improved survival (P<0.01) in all ages groups except in patients 85 years or greater, where there was no difference (P=0.16). All-polyethylene tibial components had improved survival (P<0.005) for all BMI's except in the morbidly obese (BMI ≥40) where there was no difference (P=0.20). (3) Is there an increased risk of post-operative infection? Metal-backed tibial components were found to have an increased risk of infection (HR 1.60, P=0.003). (4) Is there a difference in the rate of reoperation and post-operative complications? Metal-backed tibial components were found to have an increased risk of reoperation (HR 1.84, P<0.0001).

Conclusions: The use of all-polyethylene tibias should be considered for the majority of patients, regardless of age and BMI.

From 1985 through 1997, 56 isolated tibial insert exchange revisions were performed at our institution. Fifty-five patients with wear or instability were included. Those with loosening of any of the components, history of infection, severe knee stiffness or problems with the extensor mechanism were excluded. There were 29 males (1 bilateral) and 26 female patients with a mean age of 66 years (range 35 to 83 years) at the time of revision surgery. Twenty-seven inserts were exchanged based on ligamentous instability, 24 because of insert wear or breakage including two cases of polyethylene dislodgment from the tibial base-plate and 5 for other reasons. Twelve knees had one to three prior revisions. Surveillance from index arthroplasty averaged 8.3 years (range 1.6 to 16.2 years) and since revision 4.6 years (range 2 to 14 years).

Knee Society and Function Scores improved from 56 and 50.9 prior to revision to 76 and 59 at final surveillance, respectively. Fourteen (25%) of the 56 knees subsequently required re-revision after a mean of only three years (range 0.5 to 6.8) from tibial insert exchange. The cumulative survival at 5.5 years was 63.5% (95% CI=+/−14.4, n=19). Of the 27 patients with preoperative instability, eight were revised and another four were considered as failures due to severe pain. Of the 24 failed inserts, five were re-revised, one was amputated as a result of chronic ankle osteomyelitis concomitant to a chronically painful arthroplasty, and another two inserts failed due to severe pain.

Isolated tibial insert exchange led to a surprisingly high early failure rate. Tibial insert exchange should therefore be undertaken with caution as an isolated method of total knee revision surgery even in those circumstances for which the modular insert was designed and felt to be of greatest value.

The majority of patients who develop hip arthritis have a mechanical abnormality of the joint. The structural abnormalities range from instability (DDH) to impingement. Impingement leads to osteoarthritis by chronic damage to the acetabular labrum and adjacent cartilage.

In situations of endstage secondary DJD, hip arthroplasty is the most reliable treatment choice. In young patients with viable articular cartilage, joint salvage is indicated. Treatment should be directed at resolving the structural abnormalities that create the impingement.

Femoral abnormalities corrected by osteotomy or increased head-neck offset by chondro-osteoplasty creating a satisfactory head-neck offset. This can safely be done via anterior surgical dislocation. The acetabular-labral lesions can be debrided and/or repaired. Acetabular abnormalities should be corrected by “reverse” PAO in those with acetabular retroversion or anterior acetabular debridement in those with satisfactory posterior coverage and a damaged anterior rim.

Often combinations of the above are indicated.

This talk will also update issues related to hip impingement and joint salvage surgery that have arisen over the past year.

Introduction

Recent gains in knowledge reveal that the ideal acetabular cup position is in a narrower range than previously appreciated and that position is likely different based on femoral component anteversion. For that reason more accurate acetabular cup positioning techniques will be important for contemporary THA. It is well known that malalignment of the acetabular component in THA may result in dislocation, reduced range of motion or accelerated wear. Up to 8% of THA patients have cups malaligned in version by more than ±10° outside of the Lewinnek safe zone. This type of malalignment may result in dislocation of the femoral head and instability of the joint within the first year, requiring reoperation. Reported incidences of reoperation are 1-9% depending on surgical skills and technique. In addition, cup malalignment is becoming increasingly important as adoption of hard on hard bearings increases as the success of large head hard on hard bearings seems to be more sensitive to cup positioning. This study reports the accuracy of a haptic robotic system to ream the acetabulum and impact an acetabular cup compared to manual instrumentation.

Purpose of the study: Few data are available concerning the proper management of patients with a periprosthetic fracture of the hip who presents biological signs of inflammation (increased WBC, sedimentation rate, or C-reactive protein). The purpose of this work was to determine the prevalence of elevated biological markers in this type of patient and to determine the reliability of such markers for the diagnosis of periprosthetic infection.

Material and methods: A periprosthetic hip fracture was diagnosed in 204 patients from 2000 to 2006. The WBC count, the sedimentation rate and the serum CRP level were noted at admission to the emergency ward. The diagnosis of infection was confirmed by at least two positive bacteriological samples of tissue biopsy and/or joint fluid collected at surgery. A statistical analysis was conducted to determine the prevalence of elevated biological markers of inflammation, the sensitivity, their specificity and their positive predictive value for deep infection.

Results: Twenty-one patients (11.6%) developed a periprosthetic infection. Among the 204 patients, the WBC count increased in 16.2%, sedimentation rate in 33.3% and CRP in 50.5%. The sensitivity was 24% (WBC), 50% (sedimentation rate) and 83% (CRP). The specificity was 85% (WBC), 69% (sedimentation rate) and 56% (CRP). The positive predictive value was low (18, 21 and 29% respectively).

Discussion: Markers of inflammation are frequently ordered before surgery to search for infection but can be elevated for various reasons. Most often, these markers are elevated because of the patient’s general status and are thus related to other co-morbid conditions and/or reaction to the new fracture. In this population, the WBC count did not contribute to the diagnosis of infection as only 24% of the infected patients had a high count. CRP and sedimentation rate and the WBC count had low positive predictive values.

Conclusion: This study shows that an isolated elevation of biological markers of inflammation in a patient with a periprosthetic fracture is not a good indicator of infection.

Purpose of the study: Acetabular version is a most important parameter for repositioning the acetabular fragment during periacetabular osteotomy. Recently, a few studies have presented a significant number of dysplastic hips with acetabular retroversion. There have not however been any studies devoted specifically to the severity of bilateral acetabular retroversion. The purpose of this work was to determine the incidence of bilateral retroversion in patients undergoing periacetabular osteotomy for dysplasia in order to identify and validate a retroversion index which would be predictive of the degree of retroversion. This index could be added to congenital hip dysplasia classifications to include acetabular version.

Material and methods: The Lequesne lateral view of the hip was obtained in 174 patients (348 hips, 137 women and 37 men, mean age 30 years) undergoing periacetabular osteotomy for symptomatic dysplasia. One hundred ninety-five hips (56%) were operated on and 153 (44%) were considered normal or non-symptomatic and were not operated. The following parameters were noted for each hip: VCE, VCA, HTE, femoral head extrusion, index of acetabular depth, crossing-over, retroversion index. The retroversion index was checked on a bone model of the pelvis which was x-rayed in the neutral position then turned progressively. Statistical data were analyzed with SAS.

Results: Five percent of the operated hips presented neutral version, 53% anteversion and 42% retroversion. Twenty-four percent of the non-operated hips were normal, 22% presented pure retroversion and 54% were dysplastic. All of the measurements were significantly deviated towards dysplasia for operated hips, with the exception of the retroversion index and the VCA.

Discussion: These data validated the retroversion index and confirmed that one out of three dysplastic hips displays retroversion. In addition, it would appear that for dysplastic hips with retroversion, the degree of lateral coverage or the HTE angle determines whether surgery is needed or not and not the degree of retroversion. But as pure retroversion can be symptomatic in itself, and since the majority of these version or cover anomalies can be treated by periacetabular osteotomy, we propose a classification of hip dysplasia included acetabular version.

Conclusion: This classification is designed as an aid for the orthopedic surgeon for reorienting the acetabular fragment to obtain the optimal position.

Complete debridement for synovial chondromatosis of the hip joint is difficult to achieve by standard surgical approaches. The goal of this study was to report preliminary experiences and results for treatment of this disease by a recently developed technique for surgical dislocation of the hip. The technique offers a safe and entire access to the hip joint in order to perform a synovectomy and complete joint debridement. This technique was applied in 8 patients with mean age of 38 years (24–65yrs.). This was done as the initial treatment in 6 patients and for recurrent disease after previous surgery in 2 patients. The mean follow-up was 4.3 years (2–10yrs.). None of the patients had recurrence of synovial chondromatosis. Six of 8 patients showed a good or excellent clinical result without progressive radiographic signs of osteoarthritis (OA). None of the patients developed avascular necrosis. 2 patients underwent total hip joint replacement after 5 and 10 years. One of these two patients had three previous surgeries for recurrence. The other one had the surgical dislocation as initial treatment. Both presented with distinct radiographic signs of OA prior to the index surgery. The technique of surgical dislocation allowed a safe and reliable joint debridement for synovial chondromatosis of the hip. The results indicate that this approach is successful when performed at an early stage without distinct signs of OA.