Cup-cage constructs in revision total hip arthroplasty for pelvic discontinuity.

Aims: Pelvic discontinuity is a challenging acetabular defect without a consensus on surgical management. Cup-cage reconstruction is an increasingly used treatment strategy. The present study evaluated implant survival, clinical and radiological outcomes, and complications associated with the cup-cage construct. Methods: We included 53 cup-cage construct (51 patients) implants used for hip revision procedures for pelvic discontinuity between January 2003 and January 2022 in this retrospective review. Mean age at surgery was 71.8 years (50.0 to 92.0; SD 10.3), 43/53 (81.1%) were female, and mean follow-up was 6.4 years (0.02 to 20.0; SD 4.6). Patients were implanted with a Trabecular Metal Revision Shell with either a ZCA cage (n = 12) or a TMARS cage (n = 40, all Zimmer Biomet). Pelvic discontinuity was diagnosed on preoperative radiographs and/or intraoperatively. Kaplan-Meier survival analysis was performed, with failure defined as revision of the cup-cage reconstruction. Results: The five-year all-cause survival for cup-cage reconstruction was 73.4% (95% confidence interval (CI) 61.4 to 85.4), while the ten- and 15-year survival was 63.7% (95% CI 46.8 to 80.6). Survival due to aseptic loosening was 93.4% (95% CI 86.2 to 100.0) at five, ten, and 15 years. The rate of revision for aseptic loosening, infection, and dislocation was 3/53 (5.7%), 7/53 (13.2%), and 6/53 (11.3%), respectively. The mean leg length discrepancy improved (p < 0.001) preoperatively from a mean of 18.2 mm (0 to 80; SD 15.8) to 7.0 mm (0 to 35; SD 9.8) at latest follow-up. The horizontal and vertical hip centres improved (p < 0.001) preoperatively from a mean of 9.2 cm (5.6 to 17.5; SD 2.3) to 10.1 cm (6.2 to 13.4; SD 2.1) and 9.3 cm (4.7 to 15.8; SD 2.5) to 8.0 cm (3.7 to 12.3; SD 1.7), respectively. Conclusion: Cup-cage reconstruction provides acceptable outcomes in the management of pelvic discontinuity. One in four constructs undergo revision within five years, most commonly for periprosthetic joint infection, dislocation, or aseptic loosening.

Subsidence of a Single-Taper Femoral Stem in Primary Total Hip Arthroplasty: Characterization, Associated Factors, and Sequelae.

BACKGROUND: We characterized subsidence of an uncemented single-taper femoral stem in primary total hip arthroplasty (THA), determined factors associated with subsidence, and evaluated the impact of subsidence on outcome. METHODS: This retrospective study included 502 primary THAs performed using a single-taper stem in Dorr type-A and type-B femora between 2014 and 2018. Subsidence was measured based on distance from the greater trochanter to stem shoulder on calibrated X-rays. Demographics, case-specific data, and outcomes were collected. Changes in subsidence and variables associated with subsidence were determined. RESULTS: Stem subsidence was 1.5 ± 2.3 mm, 1.6 ± 2.0 mm, 2.0 ± 2.6 mm, 2.3 ± 2.3 mm, 2.6 ± 2.5 mm, and 2.7 ± 3.0 mm at 6 weeks, 3 months, 6 months, 1 year, 2 years, and ≥3 years from THA, respectively. Subsidence across all patients at final mean follow-up of 24 months (range, 1 to 101 months) was 2.2 ± 2.6 mm. Pairwise comparison demonstrated that subsidence occurred predominantly within the first 6 months. Significant subsidence (≥5 mm) occurred in 17.3% and was associated with a body mass index (BMI) ≥25 (P = .04). Dorr type, age, sex, and American Society of Anesthesiologists class were not associated with subsidence. There were 2 patients (0.4%) who underwent a revision that could be attributed to subsidence. There was no association between subsidence and pain, limp, need for ambulatory aid, or analgesic use. CONCLUSION: In primary THAs performed using a single-taper prosthesis, average subsidence was 2.2 mm and significant subsidence occurred in 17.3%. Patient BMI was associated with subsidence. Revision surgery related to subsidence was infrequent (0.4%).

Clinical and Functional Outcomes of Extended Trochanteric Osteotomy in 2-Stage Revision Total Hip Arthroplasty for Periprosthetic Joint Infection: A Systematic Review and Meta-Analysis.

BACKGROUND: Extended trochanteric osteotomy (ETO) has long been used in 2-stage revision surgeries of the hip, for both aseptic and septic indications. The purpose of this systematic review is to summarize the cumulative occurrence rates of the clinical and functional outcomes associated with the use of ETO in 2-stage revision total hip arthroplasty for periprosthetic joint infection. METHODS: PubMed/MEDLINE and the Cochrane Database of Systematic Reviews databases were searched for articles published from January 1980 to January 2022 using the following keywords: "extended" AND "trochanteric" AND "osteotomy" AND "infection." Cumulative occurrence rates of outcomes and complications were calculated. A fixed-effects model and a 95% CI were applied. A P value of .05 was considered the significance threshold. RESULTS: Nine studies were in full compliance with the inclusion criteria, with a total population size across all studies of 378. Union and infection eradication rates among studies were 95.1% (95% CI, 92.7-97.1, P = .018) and 94.0% (95% CI, 91.1-96.4, P = .089), respectively. Postoperation complications occurred in 15.34% of patients (95% CI, 10.34-21.22, P = .066). Occurrence rates for stem subsidence, dislocation, and femoral fractures were 6.2% (95% CI, 3.3-9.9, P = .187), 7.6% (95% CI, 4.8-10.9, P = .075), and 9.1% (95% CI, 5.8-13, P = .106), respectively. CONCLUSION: With high rates of union and infection eradication, and low rates of postoperation complications, this study concludes the use of ETO in performing 2-stage revision total hip arthroplasty for the septic hip to be effective and safe.

Outcomes of Plug Osteochondral Allograft Transplantation With or Without Concomitant Osteotomy for Cartilage Defects in the Knee: Minimum 2-year Follow-up.

INTRODUCTION: Isolated osteochondral defects of the knee can cause notable pain and disability. Osteochondral allograft (OCA) transplantation using trephined plug grafts is a highly effective, often curative, treatment option. In knees with malalignment into the transplanted compartment, osteotomy can be done concurrently. This study investigates early-to-midterm survivorship, as well as clinical and radiographic outcomes, of plug OCAs with and without concomitant osteotomy in the knee. METHODS: Plug OCA was done on active, young to middle-aged patients with osteochondral defects ≤4 cm diameter. Prospectively collected data for 102 patients who underwent plug OCA between 2004 and 2020 were reviewed. Survivorship according to Kaplan-Meier analysis was the primary outcome. Failure was defined as conversion to total knee arthroplasty or repeat allograft. Clinical and radiographic outcomes were evaluated using the modified Hospital for Special Surgery (mHSS) score and Kellgren-Lawrence grading. RESULTS: Eighty-six patients with a mean age of 29 ± 9.7 years (15 to 54) and a mean follow-up of 6.8 ± 3.7 years (2 to 15.9) were studied. Concomitant realignment osteotomy was done in 66 patients (76.7%). Graft survivorship was 100%, 93.8% (95% confidence interval 90.8% to 96.8%), and 89.7% (95% confidence interval 85.6% to 93.8%) at 2, 5, and 10 to 15 years, respectively. Six grafts (7.0%) required knee arthroplasty at a mean of 4.6 ± 1.8 years (2.2 to 7.1). Most common reasons for revision surgeries with graft retention included implant removal (11.6%), débridement (8.1%), and repeat osteotomy (5.8%). The mean mHSS score of 90.8 ± 10.4 (51 to 100) at the final follow-up was significantly higher than the preoperative value of 72.5 ± 12.1 (36 to 90) (P < 0.001). Subgroup analyses revealed a markedly greater risk of failure in grafts with a diameter of 30 mm or larger. DISCUSSION: Plug OCA with or without concurrent realignment osteotomy resulted in an excellent graft survival of 93% at a mean of 6.8 years, with reliable functional improvement demonstrated by notable improvements in mHSS knee scores.

Mid-term outcomes of the Wagner Cone Prosthesis™ stem for developmental dysplasia of the hip: minimum two year follow-up.

PURPOSE: Treatment of symptomatic developmental dysplasia of the hip (DDH) requires a technically demanding total hip arthroplasty (THA) reconstruction. In patients with DDH, prostheses can be difficult to implant and often face the risk of fracture, mismatch, and loosening. The Wagner Cone Prosthesis™ is a tapered, conical stem which can improve treatment success in this population. We look at midterm survivorship and outcomes of THA for DDH using the Wagner Cone Prosthesis™. METHODS: We retrospectively analyzed 28 patients (33 hips) with DDH undergoing THA using the Wagner Cone Prosthesis™ between January 2008 and January 2020. Ten, nine, and fourteen included patients were classified as Hartofilakidis A, B, and C, respectively. Survivorship according to Kaplan-Meier analysis was the primary outcome, with re-operation and revision as endpoints. The Oxford hip score (OHS) was used to assess clinical outcome. We used multivariate analysis to determine predictors of poor outcomes. The average follow-up was 4.6 years, with a minimum of two years. RESULTS: Kaplan-Meier survivorship over the 13-year study period was 93.9 ± 4.2% for all-cause revision as an endpoint and 96.9 ± 3.1% for stem revisions only. The overall reoperation rate was 6.1%, with periprosthetic fracture and dislocation being reasons for re-operation. No patients were revised for aseptic loosening, and no patients were revised for subsidence. OHS improved from 19.3 ± 9.6 (4-39) pre-operatively to 37.6 ± 8.4 (19-48) at latest follow-up (p < 0.05). CONCLUSION: In patients with DDH, THA with the Wagner Cone Prosthesis™ demonstrates excellent clinical, radiographic, and patient-reported functional outcomes at midterm follow-up.

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

BACKGROUND: During 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. METHODS: We 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. RESULTS: The 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). CONCLUSION: The 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.

Hip Arthroplasty With the Use of a Reconstruction Cage and Porous Metal Augment to Treat Massive Acetabular Bone Loss: A Midterm Follow-Up.

BACKGROUND: Acetabular reconstruction in the context of massive acetabular bone loss is challenging. In rare scenarios where the extent of bone loss precludes shell placement (cup-cage), reconstruction at our center consisted of a cage combined with highly porous metal augments. This study evaluates survivorship, complications, and functional outcomes using this technique. METHODS: Patients with minimum 2-year follow-up were included. Baseline characteristics were collected. Preintervention and postintervention ambulatory scores were collected. Kaplan-Meier (KM) survival analysis for cage failure requiring revision surgery was conducted. Binomial regression analysis was performed to assess for correlation of aseptic cage failure with baseline characteristics. Preintervention and postintervention ambulatory aid requirements were compared. RESULTS: A total of 41 patients were identified. Mean follow-up was 6.4 years (range 2.8-11.0). Four (9.8%) aseptic cage revisions were identified. Aseptic KM survival analysis was 87.4% (95% confidence interval 75.3-99.6) at 10 years. Aseptic KM survival was 45.0% versus 92.8% at 9 years (P = .14) for patients with vs without pelvic discontinuity. KM survival for all-cause failure was 61.6% (95% confidence interval 44.0-79.2) at 10 years. Binomial regression did not demonstrate correlation of cage failure with baseline characteristics. Wilcoxon signed-rank test demonstrated a significant reduction in ambulatory aide requirement after surgery (mean rank 11.47 vs 9.00, Z = -2.95, P = .003). CONCLUSION: In scenarios of massive acetabular bone loss where a cup-cage is not a viable option, good survivorship free from aseptic cage failure can be expected at mid-term follow-up using an antiprotrusio cage combined with porous metal augments. Success requires extensive experience in revision surgery.

Irregular porous titanium enhances implant stability and bone ingrowth in an intra-articular ovine model.

Two commercially available porous coatings, Gription and Porocoat, were compared for the first time in a challenging intra-articular, weight-bearing, ovine model. Gription has evolved from Porocoat and has higher porosity, coefficient of friction, and microtextured topography, which are expected to enhance bone ingrowth. Cylindrical implants were press-fit into the weight-bearing regions of ovine femoral condyles and bone ingrowth and fixation strength evaluated 4, 8, and 16 weeks postoperatively. Biomechanical push-out tests were performed on lateral femoral condyles (LFCs) to evaluate the strength of the bone-implant interface. Bone ingrowth was assessed in medial femoral condyles (MFCs) as well as implants retrieved from LFCs following biomechanical testing using backscattered electron microscopy and histology. By 16 weeks, Gription-coated implants exhibited higher force (2455 ± 1362 vs. 1002 ± 1466 N; p = 0.046) and stress (12.60 ± 6.99 vs. 5.14 ± 7.53 MPa; p = 0.046) at failure, and trended towards higher stiffness (11,510 ± 7645 vs. 5010 ± 8374 N/mm; p = 0.061) and modulus of elasticity (591 ± 392 vs. 256 ± 431 MPa; p = 0.061). A strong, positive correlation was detected between bone ingrowth in LFC implants and failure force (r = 0.93, p < 10-13 ). By 16 weeks, bone ingrowth in Gription-coated implants in MFCs was 10.50 ± 6.31% compared to 5.88 ± 2.77% in Porocoat (p = 0.095). Observations of the bone-implant interface, made following push-out testing, showed more bony material consistently adhered to Gription compared to Porocoat at all three time points. Gription provided superior fixation strength and bone ingrowth by 16 weeks.

3D-Printed Personal Protective Face Shields During the COVID-19 Pandemic: A Survey of Canadian Frontline Workers.

Background During the coronavirus disease 2019 pandemic, three-dimensional (3D) printing was utilized to rapidly produce face shields for frontline workers in response to an acute shortage of personal protective equipment (PPE). In this study, we examine the perceived utility and performance of 3D-printed (3DP) face shields through a survey of frontline workers in Ontario, Canada. Methodology Frontline workers who received community-produced 3DP face shields from the Canadian initiative "3DPPE GTHA" (March-December 2020) were invited to participate in the study. The survey response rate was 54.3%. Of 63 respondents, 39 were patient-facing and 24 were community-facing frontline workers. Participants were asked to rate performance measures in 10 categories on a five-point Likert scale. Data were categorized by organization and frontline worker type, and a t-test was used to determine statistically significant differences among subgroups. Results The mean preference for 3DP face shields among respondents was 3.2 out of 5 (95% confidence interval [CI]: 2.1-4.3). Community-facing respondents reported significantly greater overall utility scores for 3DP face shields (3.58, 95% CI: 3.38-3.79) compared to respondents working in a patient-facing profession (2.95, 95% CI: 2.77-3.13; p < 0.05). However, no differences were reported in portability and compatibility with other PPE. Respondents from organizations with large service volumes reported significantly lower overall utility scores (2.67, 95% CI: 2.44-2.89) than respondents in organizations with smaller service volumes (3.45, 95% CI: 3.28-3.62; p < 0.05). Conclusions Community-facing frontline workers and those from smaller service volume organizations endorse higher utility for 3DP face shields than patient-facing frontline workers. Despite this, frontline workers generally rate 3DP face shields positively. 3DP face shields are a viable option for personal and community use and can be used to supplement supply in a community setting.

Intraoperative measurement of acetabular component position using imageless navigation during revision total hip arthroplasty.

BACKGROUND: Acetabular component malposition is a major cause of dislocation following total hip arthroplasty (THA). Intellijoint HIP is an imageless navigation tool that has been shown to provide accurate intraoperative measurement of cup position during primary THA without substantially increasing operative time. However, its accuracy in revision THA has not been evaluated. This study therefore aims to assess the accuracy of Intellijoint HIP in measuring cup inclination and anteversion in comparison with computed tomography (CT) during revision THA. METHODS: Intellijoint HIP was used to measure the position of the preexisting cup in 53 consecutive patients undergoing revision THA between December 2018 and February 2020. Two authors blinded to the intraoperative navigation measurements also independently measured cup position using preoperative CT according to Murray's radiographic definitions. Pearson correlation coefficients with 95% confidence intervals (CIs), paired t tests and Bland-Altman plots were used to assess agreement between navigation- and CT-measured cup position. Statistical analysis was performed using GraphPad Prism, with p values less than 0.05 indicating statistical significance. RESULTS: There was excellent agreement between navigation and CT measurements for both cup inclination (r = 0.89, 95% CI 0.81-0.93) and anteversion (r = 0.93, 95% CI 0.88-0.96), with the mean absolute difference being 5.2º (standard deviation [SD] 4.0º) for inclination and 4.8º (SD 5.4º) for anteversion. The navigation measurement was within 10º of the radiographic measurement in 47 of 53 (88.7%) cases for inclination and 46 of 53 (86.8%) cases for anteversion. CONCLUSION: Imageless navigation demonstrated excellent correlation and agreement with CT measurements for both inclination and anteversion over a wide range of acetabular component positions.

Outcomes of Bulk Fresh Osteochondral Allografts for Cartilage Restoration in the Knee.

BACKGROUND: Symptomatic osteochondral defects of the knee in young patients can cause substantial disability and predispose to osteoarthritis. Fresh osteochondral allografts (FOCAs) are a treatment option for such defects. With our institution having one of the longest-running FOCA programs, we investigated the long-term outcomes of bulk FOCA in the knee, focusing on graft survivorship, function, complications, and reoperation. METHODS: A total of 244 patients underwent bulk FOCA in the knee from 1972 to 2018, with a mean age of 37.8 years (range, 10 to 75 years) and a mean follow-up of 9.0 years (range, 1.0 to 29.8 years). Cartilage defects were very large and uncontained, such that they were not amenable to plug transplantation. Survivorship according to Kaplan-Meier analysis was the primary outcome, and failure was defined as conversion to total knee arthroplasty, repeat allograft, graft removal, knee arthrodesis, or amputation. Functional outcome was evaluated with use of the modified Hospital for Special Surgery (mHSS) score, and radiographic evidence of osteoarthritis was classified with use of the Kellgren-Lawrence grading scale. RESULTS: Graft survivorship was 86.6% at 5 years, 73.3% at 10 years, 58.1% at 15 years, 43.7% at 20 years, 31.9% at 25 years, and 22.6% at 30 years. The most common complications were pain (14.8%), malalignment (13.9%), and stiffness (5.8%). A total of 93 grafts (38.1%) failed at a mean of 11.0 years (range, 0.5 to 34.0 years). The mean mHSS score improved significantly, from 68.7 (range, 19 to 91) preoperatively to 80.3 (range, 52 to 100) at the time of the latest follow-up (p < 0.001). Preoperative mHSS score had a negative correlation with Kellgren-Lawrence grade at the time of the latest follow-up. Multivariate analysis revealed that graft location (i.e., medial-sided or multiple grafts) and increased age were significantly negatively associated with survival. Ten-year survival was >80% in patients below 50 years old, but <40% in patients >60 years old. CONCLUSIONS: Bulk FOCA provided promising long-term graft survival and functional improvement in patients <50 years old. It can delay or prevent the need for total knee arthroplasty in young patients. Older patients and patients with a medial-sided graft, or multiple grafts within the same knee, had a less favorable prognosis. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Return to Paralympic Rowing After Partial Joint Transplantation: A Case Report.

CASE: A 24-year-old competitive rower suffered a severe road injury to the medial aspect of his knee. He was referred to us for a partial joint transplantation consisting of a medial tibiofemoral fresh osteochondral allograft (FOCA), medial collateral ligament, meniscal allograft, and osteotomy. Two years after reconstruction, the patient won a bronze medal in the Summer Paralympics. At the 6-year follow-up, he demonstrates excellent clinical and radiographic outcomes and high satisfaction. CONCLUSION: For extensive knee injuries with large, complex defects, FOCA with concomitant meniscal allograft transplantation, ligamentous allograft, and osteotomy may be considered in high-demand athletes who wish to return to play.

Periacetabular Osteotomy and Femoral Head Allograft for Hip Dysplasia and Femoral Head Cyst: A Case Report.

CASE: A 34-year-old woman with developmental dysplasia of the hip (DDH) presented with chronic left hip pain related to a femoral head cyst. The patient strongly preferred a joint-preserving option. Periacetabular osteotomy (PAO) has shown reliable options for managing DDH, and femoral head fresh osteochondral allograft (FOCA) can be performed for cysts. We performed these procedures concomitantly for the first time. At 1-year follow-up, the patient had functional, pain-free motion and high satisfaction. CONCLUSION: PAO and femoral head FOCA can be performed concomitantly with a common, anterior hip approach. They are a viable, joint-preserving option for patients with DDH and osteochondral lesions.

Midterm Outcomes After Reconstruction of Superolateral Acetabular Defects Using Flying Buttress Porous Tantalum Augments During Revision Total Hip Arthroplasty.

BACKGROUND: Porous tantalum augments are versatile tools in reconstructing complex acetabular defects during revision total hip arthroplasty (THA). This study examines the clinical and radiographic outcomes of porous tantalum augments placed in the type I (flying buttress) configuration at two to 17-year follow-up in the largest cohort to-date in the literature. METHODS: We retrospectively analyzed 59 consecutive revision THAs involving the use of flying buttress augments between 2003 and 2018. The mean patient age and follow-up duration were 63.9 ± 11.6 years (range, 35-87) and 8 years (range, 2-17), respectively. The Oxford hip score was used to assess clinical outcome. The modified Moore classification was used to assess acetabular augment and shell osseointegration. Kaplan-Meier survival analysis with 95% confidence interval (CI) was used to assess implant survivorship. RESULTS: The mean Oxford hip score improved from 15.9 ± 6.2 preoperatively to 35.0 ± 6.5 at a mean follow-up of eight years (P < .0001). Radiographic assessment using the modified Moore classification demonstrated five signs of osseointegration in 49 hips (83.1%), four signs in six hips (10.2%), three signs in one hip (1.7%), and one sign in one hip (1.7%). Kaplan-Meier analysis demonstrated ten-year survivorship of 88.9% (95% CI 74.4-95.4) with all-cause revision as end point and 94.3% (95% CI 83.1-98.2) with revision for acetabular aseptic loosening as end point. CONCLUSION: Treatment of superolateral acetabular defects during revision THA using porous tantalum augments placed in the type I (flying buttress) configuration provides excellent implant survivorship and favorable clinical outcomes at mid-term follow-up. LEVEL OF EVIDENCE: Therapeutic Level IV.

Biomechanical optimization of the far cortical locking technique for early healing of distal femur fractures.

This finite element study optimized far cortical locking (FCL) technology for early callus formation in distal femur fracture fixation with a 9-hole plate using FCL screws proximal to, and standard locking screws distal to, the fracture. Analyses were done for 120 possible FCL screw configurations by varying FCL screw distribution and number. A hip joint force of 700 N (i.e. 100% x body weight) was used, which corresponds to a typical 140 N "toe-touch" foot-to-ground force (i.e. 20% x body weight) suggested to patients immediately after surgery. Increased FCL screw distribution (i.e. shorter plate working length) caused a decrease at the medial side and an increase at the lateral side of the axial interfragmentary motion (AIM), mildly affected shaft and condylar cortex Von Mises max stress (σMAX), increased plate σMAX, and decreased shaft FCL screw and condylar locking screw σMAX. Increased FCL screw number decreased AIM and σMAX on the shaft cortex, condylar cortex, plate, and FCL screws, but not condylar screws. The optimal FCL screw configuration had 3 FCL screws in plate holes #1, 5, and 6 (proximal to distal) for optimal AIM of 0.2 - 1 mm and reduce shear fracture motion, thereby encouraging early callus formation.

Revision Hip Arthroplasty Using a Porous-coated or Taper ZMR Implant: Minimum 10-year Follow-up of Implant Survivorship.

INTRODUCTION: The Zimmer Modular Revision hip (ZMR) system is available in two stem options, a porous-coated cylindrical (PCM) and a taper (TM) stem. Several concerns have been reported regarding modular implants. Specifically, because of early junctional fractures, the ZMR system was redesigned with a wider modular interface. As such, we designed a study assessing long-term ZMR survivorship and functional and radiographic outcomes. METHODS AND MATERIALS: A search of our institutional research database was performed. A minimum 10-year follow-up was selected. The following two cohorts were created: PCM and TM stems. The Kaplan-Meier survival analysis was performed, and causes of stem failure requiring revision surgery were collected. Functional outcomes as per the Harris Hip Score and radiographic stem stability were assessed as per the Engh classification. RESULTS: A total of 146 patients meeting the inclusion criteria were available for follow-up (PCM = 68, TM = 78). The mean follow-up was 13.4 years clinically and 11.1 years radiographically for the PCM cohort. Similarly, the TM cohort had a follow-up of 11.1 years clinically and 10.5 years radiographically. The Kaplan-Meier survivorships were 87.1% and 87.8% at 15 years for the PCM and TM cohorts, respectively. The most common cause of failure requiring revision surgery overall was aseptic loosening (PCM = 1.4%, TM = 5.6%). The mean postoperative Harris Hip Score was as follows: PCM = 71.2 and TM = 64.7. Engh type I or II stem ingrowth was as follows: PCM = 85% and TM = 68%. DISCUSSION: Good survivorship using the ZMR stem system can be expected at up to 15 years. Aseptic loosening remains the most commonly encountered problem for both PCM and TM stems. Previously identified modular junctional weakness seem to have been addressed.

Does Trochanteric Osteotomy Length Affect the Amount of Proximal Trochanteric Migration During Revision Total Hip Arthroplasty?

BACKGROUND: Nonunion and proximal trochanteric migration is a known complication of trochanteric osteotomy. This study examines the effect of osteotomy length on proximal greater trochanter (GT) migration. METHODS: We analyzed 113 modified trochanteric slide osteotomies and 73 extended trochanteric osteotomies performed between 2008 and 2016. All osteotomies were fixed using cerclage wires and had minimum 6-month radiographic follow-up. Spearman correlations were used to assess association between osteotomy length and GT migration distance. Chi-squared test and logistic regression were used to assess association between patient and surgical factors and GT migration >1 cm. Receiver operating characteristic curves were constructed to determine the optimal cutoff osteotomy length for predicting GT migration >1cm. RESULTS: Mean osteotomy length was 6.1 cm (range 3-12) for modified trochanteric slide osteotomies and 14.8 cm (range 8-23) for extended trochanteric osteotomies. Osteotomy length was negatively correlated (r = -0.340, P < .001) with GT migration distance. Longer osteotomy length was protective against GT migration >1 cm (odds ratio 0.67, P = .002). Receiver operating characteristic curve analysis demonstrated an optimal cutoff osteotomy length of 9.8 cm for predicting GT migration >1 cm (sensitivity 0.971, specificity 0.461). Among osteotomies <10 cm, those fixed using at least one distal wire below the lesser trochanter and vastus ridge demonstrated less mean GT migration (3.86 vs 7.12 mm, P = .009) and higher mean union rate (68.8% vs 31.2%, P < .001). CONCLUSION: Osteotomies shorter than 10 cm are at higher risk of developing proximal GT migration >1 cm. A distal cerclage wire below the lesser trochanter and vastus ridge may help decrease the amount of GT migration. LEVEL OF EVIDENCE: Prognostic Level IV.

Long-Term Results of Treating Large Posttraumatic Tibial Plateau Lesions with Fresh Osteochondral Allograft Transplantation.

BACKGROUND: The use of fresh osteochondral allograft (FOCA) transplantation is a treatment option for large posttraumatic tibial osteochondral defects in young, high-demand patients. We aimed to assess the long-term outcomes of this procedure and factors impacting graft survivorship. METHODS: Evaluated were patients with a posttraumatic tibial plateau defect of >3 cm in diameter and >1 cm in depth who were treated with use of a FOCA, with or without a realignment osteotomy, before September 2007. The primary outcome was survivorship according to Kaplan-Meier analysis, with conversion to arthroplasty or another allograft procedure as the end point. The secondary outcome was the functional outcome of knees with a surviving FOCA, as assessed using the modified Hospital for Special Surgery (mHSS) scoring system. Multivariate Cox regression analysis of the role of potential variables was performed for both outcomes. RESULTS: Included were 113 patients (67 female) with a mean age at the time of the index surgery of 43 years (range, 24 to 72 years) and a mean follow-up of 13.8 years (range, 1.7 to 34 years). Forty-eight conversions to arthroplasty or another FOCA procedure had been performed at a mean of 11.6 years (range, 1.7 to 34 years) after the index surgery. The remaining 65 patients had a mean follow-up of 15.5 years (range, 4.3 to 31.7 years). The mean mHSS score among those with a surviving FOCA was 85.5 (range, 56 to 100) at the most recent follow-up, which was significantly higher than the preoperative value of 69 (range, 48 to 85) (p < 0.001). Graft survivorship was 90% at 5 years, 79% at 10 years, 64% at 15 years, and 47% at 20 years. Complications included infection (1.8%), nonunion (0.9%), and knee pain from hardware (8.8%). Multivariate analysis revealed that older age at the time of surgery, involvement of the medial plateau, and a higher number of previous surgeries were inversely associated with graft survivorship. Having a Workers' Compensation file was associated with less improvement in the mHSS score, and the score tended to decline over time for knees with a surviving FOCA. CONCLUSIONS: FOCA transplantation is a viable option for posttraumatic tibial osteochondral defects, with satisfactory survivorship and functional outcome. Although approximately half of the patients in our study demonstrated graft failure by 20 years, FOCA was an excellent option that delayed the need for arthroplasty. Older patients, those with medial defects, and those with multiple previous surgeries had a less favorable prognosis. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Patient and Caregiver Understanding of Prognosis After Hip Fracture.

BACKGROUND: Hip fracture (HF) is common and requires communication between patient, family, surgeons, and hospitalists. Patient and family understanding of the seriousness of HF is unclear. METHODS: We interviewed older patients (age > 65 years) hospitalized with HF at two Canadian academic hospitals, or their surrogate decision-makers (SDMs). We used qualitative methods to explore understanding of HF treatment options and prognosis. Participants estimated probability of mortality and living independently 30 days after surgery. Results were compared with estimates from the National Surgery Quality Improvement Program (NSQIP) surgical risk calculator. RESULTS: 9 patients and 3 SDMs were interviewed. Mean age of 12 patients was 82.5 years (75% female). Participants were uncertain about recovery timeline and degree of functional recovery, as well as content and duration of rehabilitation. Participants' mean estimated 30-day mortality of 6.7% did not differ significantly from estimated mortality predicted by NSQIP (7.5%; p = .88). Participants' mean estimated probability of living independently 30 days after surgery was 90.8% (range 65-100%). CONCLUSIONS: Older patients and SDMs lack understanding about prognosis and functional recovery even after providing informed consent for HF surgery. Clinical teams should improve communication of prognosis and recovery information to patients and surrogates.

The Effect of Preoperative Administration of Intravenous Tranexamic Acid During Revision Hip Arthroplasty: A Retrospective Study.

BACKGROUND: Revision hip arthroplasty poses several challenges, including the management of perioperative blood loss. Recent studies have validated the use of tranexamic acid in primary total hip arthroplasty, showing reduced blood loss and decreased number of allogenic blood transfusions. The effectiveness of tranexamic acid has not been well studied in the revision hip arthroplasty setting. METHODS: We performed a retrospective review of 1,072 patients who underwent revision hip arthroplasty at our institution from 2008 to 2016. A total of 634 patients met the inclusion criteria, and comparisons were made between 232 consecutive patients without the use of tranexamic acid and 402 consecutive patients with the use of tranexamic acid. Patients were subdivided into 4 groups based on the complexity of revision surgical procedures: (1) major revision, (2) isolated femoral component revision, (3) isolated acetabular component revision, and (4) isolated femoral head and acetabular liner exchange. Within these groups, we compared the demographic data, estimated intraoperative blood loss, perioperative blood units transfused, postoperative hemoglobin drop, and thromboembolic complications between patients receiving either tranexamic acid or no antifibrinolytic therapy. RESULTS: The primary outcomes of our study (estimated intraoperative blood loss, postoperative hemoglobin drop, and perioperative blood transfusion) were all reduced in patients who received tranexamic acid compared with patients who received no antifibrinolytic therapy. When analyzed on the basis of the complexity of surgical revision, there was a decrease in estimated intraoperative blood loss following tranexamic acid administration in the major revision group (845 compared with 1,095 mL; p < 0.001). The postoperative drop in hemoglobin was lower in the major revision group with tranexamic acid administration (by 8.9 g/L; p < 0.01) and the isolated acetabular component revision group with tranexamic acid administration (by 11.9 g/L; p < 0.001). The need for perioperative blood transfusion was reduced across all revisions treated with tranexamic acid (major revision group, 1.79 compared with 3.33 units, p < 0.001; femoral revision only, 0.97 compared with 2.25 units, p < 0.01; acetabular revision only, 0.73 compared with 1.72 units, p < 0.001; and head and liner exchange, 0.15 compared with 0.89 unit, p < 0.05). CONCLUSIONS: Based on this study, preoperative administration of intravenous tranexamic acid in revision hip arthroplasty reduces allogenic blood transfusions and perioperative blood loss. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.