Survivorship of the fixed-bearing medial unicompartmental knee arthroplasty: mean 14-year follow-up in a single medical center.

BACKGROUND: This study aimed to report the long-term survival of fixed-bearing medial unicompartmental knee arthroplasty (UKA) with a mean of 14-year follow-up, and to determine possible risk factors of failure. METHODS: We retrospectively evaluated 337 fixed-bearing medial UKAs implanted between 2003 and 2014. Demographic and radiographic parameters were measured, including pre-operative and post-operative anatomical femorotibial angle (aFTA), posterior tibial slope (PTS), and anatomical medial proximal tibial angle (aMPTA). Multivariate logistic regression analysis was applied to figure out risk factors. RESULTS: The mean follow-up time was 14.0 years. There were 32 failures categorized into implant loosening (n = 11), osteoarthritis progression (n = 7), insert wear (n = 7), infection (n = 4), and periprosthetic fracture (n = 3). Cumulative survival was 91.6% at 10 years and 90.0% at 15 years. No statistically significant parameters were found between the overall survival and failure groups. Age and hypertension were significant factors of implant loosening with odds ratio (OR) 0.909 (p = 0.02) and 0.179 (p = 0.04) respectively. In the insert wear group, post-operative aFTA and correction of PTS showed significance with OR 0.363 (p = 0.02) and 0.415 (p = 0.03) respectively. Post-operative aMPTA was a significant factor of periprosthetic fracture with OR 0.680 (p < 0.05). CONCLUSIONS: The fixed-bearing medial UKA provides successful long-term survivorship. Tibial component loosening is the major cause of failure. Older age and hypertension were factors with decreased risk of implant loosening.

Small design modifications can improve the primary stability of a fully coated tapered wedge hip stem.

Increasing the stem size during surgery is associated with a higher incidence of intraoperative periprosthetic fractures in cementless total hip arthroplasty with fully coated tapered wedge stems, especially in femurs of Dorr type A. If in contrast a stem is implanted and sufficient primary stability is not achieved, such preventing successful osseointegration due to increased micromotions, it may also fail, especially if the stem is undersized. Stem loosening or periprosthetic fractures due to stem subsidence can be the consequence. The adaptation of an established stem design to femurs of Dorr type A by design modifications, which increase the stem width proximally combined with a smaller stem tip and an overall shorter stem, might reduce the risk of distal locking of a proximally inadequately fixed stem and provide increased stability. The aim of this study was to investigate whether such a modified stem design provides improved primary stability without increasing the periprosthetic fracture risk compared to the established stem design. The established (Corail, DePuy Synthes, Warsaw, IN, US) and modified stem designs (Emphasys, DePuy Synthes, Warsaw, IN, US) were implanted in cadaveric femur pairs (n = 6 pairs) using the respective instruments. Broaching and implantation forces were recorded and the contact areas between the prepared cavity and the stem determined. Implanted stems were subjected to two different cyclic loading conditions according to ISO 7206-4 using a material testing machine (1 Hz, 600 cycles @ 80 to 800 N, 600 cycles @ 80 to 1600 N). Translational and rotational relative motions between stem and femur were recorded using digital image correlation. Broaching and implantation forces for the modified stem were up to 40% higher (p = 0.024), achieving a 23% larger contact area between stem and bone (R2 = 0.694, p = 0.039) resulting in a four times lower subsidence during loading (p = 0.028). The slight design modifications showed the desired effect in this in-vitro study resulting in a higher primary stability suggesting a reduced risk of loosening. The higher forces required during the preparation of the cavity with the new broaches and during implantation of the stem could bare an increased risk for intraoperative periprosthetic fractures, which did not occur in this study.

Complications and Reinterventions of Reverse Total Shoulder Arthroplasty in a Korean Population: 14-Year Experience in Reverse Shoulder Arthroplasty.

Background: There are few reports on the revision or reintervention of reverse total shoulder arthroplasty (RTSA) in South Korea. The purpose of this study was to evaluate the true incidence of complications and reintervention of RTSA and clinical and radiological outcomes based on our 14-year experience in RTSA in a Korean population. Methods: Between March 2008 and June 2022, 412 consecutive cases of RTSA were performed in 388 patients with an average age of 74.4 years at our institute. Excluding 23 patients lost to follow-up, 365 patients (373 shoulders including 8 bilateral cases) who underwent primary RTSA with more than 6 months of follow-up were enrolled in this study. We evaluated those who had complications or reintervention including revision RTSA for failed RTSA. Patient charts were reviewed, and clinical outcomes including clinical scores, complications, and reintervention and radiologic outcomes were evaluated at the last follow-up. Results: Among the 373 shoulders that underwent primary RTSA, complications were found in 50 patients (13.94%, 10 men and 40 women with a mean age of 75.9 ± 6.7 years [range, 51-87 years]). The causes of complications were as follows: 13 acromion, coracoid, or scapular spine fractures, 10 loosening (glenoid: 5, humeral stem: 5), 5 infections, 4 periprosthetic fractures, 2 instability, 2 neurologic complications, and 14 miscellaneous complications. Twenty patients (5.63%, 4 men and 16 women with a mean age of 74.2 ± 8.2 years [range, 51-87 years]) underwent reintervention. The interval to the first reintervention was 27.8 ± 23.1 months (range, 0.1-78 months). The causes of reintervention (20 cases) were 8 loosening (glenoid: 4, humeral stem: 4), 5 infections, 5 fractures, and 2 instability. Among them, 15 component revisions (4.02%) were performed. At the last follow-up, American Shoulder and Elbow Surgeons, University of California at Los Angeles, and Simple Shoulder Test scores were improved from 25.4, 12.4, and 1.6 preoperatively to 40.4, 16.2, and 3.2, respectively. Forward flexion (48° to 87°), abduction (52° to 79°), external rotation (18° to 22°), and internal rotation (buttock to L2) were improved. Conclusions: After primary RTSA in a Korean population, the complication, reintervention, and revision rates were 13.94%, 5.63%, and 4.02%, respectively. Careful evaluation of the complications and adequate treatments should be performed.

Reoperation risk of periprosthetic fracture after primary total hip arthroplasty using a collared cementless or a taper-slip cemented stem.

Aims: The aim of this study was to determine both the incidence of, and the reoperation rate for, postoperative periprosthetic femoral fracture (POPFF) after total hip arthroplasty (THA) with either a collared cementless (CC) femoral component or a cemented polished taper-slip (PTS) femoral component. Methods: We performed a retrospective review of a consecutive series of 11,018 THAs over a ten-year period. All POPFFs were identified using regional radiograph archiving and electronic care systems. Results: A total of 11,018 THAs were implanted: 4,952 CC femoral components and 6,066 cemented PTS femoral components. Between groups, age, sex, and BMI did not differ. Overall, 91 patients (0.8%) sustained a POPFF. For all patients with a POPFF, 16.5% (15/91) were managed conservatively, 67.0% (61/91) underwent open reduction and internal fixation (ORIF), and 16.5% (15/91) underwent revision. The CC group had a lower POPFF rate compared to the PTS group (0.7% (36/4,952) vs 0.9% (55/6,066); p = 0.345). Fewer POPFFs in the CC group required surgery (0.4% (22/4,952) vs 0.9% (54/6,066); p = 0.005). Fewer POPFFs required surgery in males with a CC than males with a PTS (0.3% (7/2,121) vs 1.3% (36/2,674); p < 0.001). Conclusion: Male patients with a PTS femoral component were five times more likely to have a reoperation for POPFF. Female patients had the same incidence of reoperation with either component type. Of those having a reoperation, 80.3% (61/76) had an ORIF, which could greatly mask the size of this problem in many registries.

The characteristics and predictors of mortality in periprosthetic fractures around the knee.

Aims: Periprosthetic fractures (PPFs) around the knee are challenging injuries. This study aims to describe the characteristics of knee PPFs and the impact of patient demographics, fracture types, and management modalities on in-hospital mortality. Methods: Using a multicentre study design, independent of registry data, we included adult patients sustaining a PPF around a knee arthroplasty between 1 January 2010 and 31 December 2019. Univariate, then multivariable, logistic regression analyses were performed to study the impact of patient, fracture, and treatment on mortality. Results: Out of a total of 1,667 patients in the PPF study database, 420 patients were included. The in-hospital mortality rate was 6.4%. Multivariable analyses suggested that American Society of Anesthesiologists (ASA) grade, history of peripheral vascular disease (PVD), history of rheumatic disease, fracture around a loose implant, and cerebrovascular accident (CVA) during hospital stay were each independently associated with mortality. Each point increase in ASA grade independently correlated with a four-fold greater mortality risk (odds ratio (OR) 4.1 (95% confidence interval (CI) 1.19 to 14.06); p = 0.026). Patients with PVD have a nine-fold increase in mortality risk (OR 9.1 (95% CI 1.25 to 66.47); p = 0.030) and patients with rheumatic disease have a 6.8-fold increase in mortality risk (OR 6.8 (95% CI 1.32 to 34.68); p = 0.022). Patients with a fracture around a loose implant (Unified Classification System (UCS) B2) have a 20-fold increase in mortality, compared to UCS A1 (OR 20.9 (95% CI 1.61 to 271.38); p = 0.020). Mode of management was not a significant predictor of mortality. Patients managed with revision arthroplasty had a significantly longer length of stay (median 16 days; p = 0.029) and higher rates of return to theatre, compared to patients treated nonoperatively or with fixation. Conclusion: The mortality rate in PPFs around the knee is similar to that for native distal femur and neck of femur fragility fractures. Patients with certain modifiable risk factors should be optimized. A national PPF database and standardized management guidelines are currently required to understand these complex injuries and to improve patient outcomes.

Revision total hip arthroplasty using a modular fluted, tapered revision femoral component and interlocking screws in Vancouver B3 periprosthetic fractures with insufficient bone at the isthmus.

Aims: Revision total hip arthroplasty in patients with Vancouver type B3 fractures with Paprosky type IIIA, IIIB, and IV femoral defects are difficult to treat. One option for Paprovsky type IIIB and IV defects involves modular cementless, tapered, revision femoral components in conjunction with distal interlocking screws. The aim of this study was to analyze the rate of reoperations and complications and union of the fracture, subsidence of the stem, mortality, and the clinical outcomes in these patients. Methods: A total of 46 femoral components in patients with Vancouver B3 fractures (23 with Paprosky type IIIA, 19 with type IIIB, and four with type IV defects) in 46 patients were revised with a transfemoral approach using a modular, tapered, cementless revision Revitan curved femoral component with distal cone-in-cone fixation and prospectively followed for a mean of 48.8 months (SD 23.9; 24 to 112). The mean age of the patients was 80.4 years (66 to 100). Additional distal interlocking was also used in 23 fractures in which distal cone-in-cone fixation in the isthmus was < 3 cm. Results: One patient (2.2%) died during the first postoperative year. After six months, 43 patients (93.5%) had osseous, and three had fibrous consolidation of the fracture and the bony flap, 42 (91.3%) had bony ingrowth and four had stable fibrous fixation of the stem. No patient had radiolucency around the interlocking screws and no screw broke. One patient had non-progressive subsidence and two had a dislocation. The mean Harris Hip Score increased from of 57.8 points (SD 7.9) three months postoperatively to 76.1 points (SD 10.7) 24 months postoperatively. Conclusion: The 2° tapered, fluted revision femoral component with distal cone-in-cone-fixation, combined with additional distal interlocking in patients with bony deficiency at the isthmus, led to reproducibly good results in patients with a Vancouver B3 fracture and Paprosky type IIIA, IIIB, and IV defects with regard to union of the fracture, subsidence or loosening of the stem, and clinical outcomes.

Unstable Vancouver B1 periprosthetic femoral fracture fixation: A biomechanical comparison between a novel C-shaped memory alloy implant and cerclage wiring.

BACKGROUND: To compare the biomechanical stability of a novel, C-shaped nickel-titanium shape memory alloy (SMA) implant (C-clip) with traditional cerclage wiring in the fixation of a Vancouver B1 (VB1) periprosthetic femoral fracture (PFF). METHODS: In total, 18 synthetic femoral fracture models were constructed to obtain unstable VB1 fracture with an oblique fracture line 8 cm below the lesser trochanter. For each model, the distal portion was repaired using a 10-hole locking plate and four distal bi-cortical screws. The proximal portion was repaired using either three, threaded cerclage wirings or three, novel C-shaped implants. Specimens underwent biomechanical testing using axial compression, torsional and four-point bending tests. Each test was performed on three specimens. RESULTS: The C-clip was statistically significantly stronger (i.e., stiffer) than cerclage wiring in the three biomechanical tests. For axial compression, medians (ranges) were 39 (39-41) and 35 (35-35) N/mm, for the C-clip and cerclage wiring, respectively. For torsion, medians (ranges) were, 0.44 (0.44-0.45) and 0.30 (0.30-0.33) N/mm for the C-clip and cerclage wiring, respectively. For the four-point bending test, medians (ranges) were 39 (39-41) and 28 (28-31) N/mm; for the C-clip and cerclage wiring, respectively. CONCLUSION: Results from this small study show that the novel, C-shaped SMA appears to be biomechanically superior to traditional cerclage wiring in terms of stiffness, axial compression, torsion and four-point bending, and may be a valuable alternative in the repair of VB1 PFF. Further research is necessary to support these results.

Does Size Really Matter? Incidence of Periprosthetic Fractures After Femoral Osteotomy in Patients With Cerebral Palsy.

OBJECTIVE: Of children, 30% to 35% with cerebral palsy (CP) develop hip subluxation or dislocation and often require reconstructive hip surgery, including varus derotation osteotomy (VDRO). A recent literature review identified postoperative fractures as the most common complication (9.4%) of VDROs. This study aimed to assess risk factors for periprosthetic fracture after VDRO in children with CP. METHODS: A total of 347 patients (644 hips, 526 bilateral hips) with CP and hip subluxation or dislocation (129 females; mean age at index VDRO: 8.6 y, SD 3.4, range: 1.5 to 17.7; 2 Gross Motor Function Classification System (GMFCS) I, 35 GMFCS II, 39 GMFCS III, 119 GMFCS IV, 133 GMFCS V, 21 unavailable) were included in this retrospective, single-group intervention (VDRO) study at a tertiary referral center. Imaging and clinical documentation for patients age 18 years or younger at index surgery, treated with VDRO were reviewed to determine demographic data, GMFCS level, surgeon, type of hardware implanted, use of anticonvulsants and steroids, type of postoperative immobilization, presence of periprosthetic fractures, fracture location and mechanism, and time from surgery to fracture. Potential determinants of periprosthetic fractures were assessed using mixed effects logistic regression. RESULTS: Of 644 hips, 14 (2.2%, 95% CI: 1.3%, 3.6%) sustained a periprosthetic fracture, at a median of 2.1 years postoperatively (interquartile range: 4.6 y, range: 1.2 mo to 7.8 y). Patients with a fracture had a median age at index surgery of 7.3 years (interquartile range: 4.3, range: 2.8 to 17.8; 1 GMFCS II, 6 GMFCS IV, 7 GMFCS V). Periprosthetic fractures were not significantly related to age at index surgery ( P = 0.18), sex ( P = 0.30), body mass index percentile ( P = 0.87), surgery side ( P = 0.16), anticonvulsant use ( P = 0.35), type of postoperative immobilization ( P = 0.40), GMFCS level ( P = 0.31), or blade plate size ( P = 0.17). Only surgeon volume significantly related to periprosthetic fracture (odds ratio = 5.03, 95% CI: 1.53, 16.56, P = 0.008), with the highest-volume surgeon also using smaller blade plates ( P < 0.01). CONCLUSIONS: Periprosthetic fractures after VDRO surgery in children with CP are uncommon, and routine hardware removal appears unnecessary. The data suggest that the common dogma of putting in the largest blade plate possible to maximize fixation may increase the risk of periprosthetic fracture. Due to the overall low fracture rate, especially when contextualized relative to the risk of hardware removal, a reactive approach to hardware removal appears warranted. LEVEL OF EVIDENCE: Level III-retrospective study (targeting varus derotational osteotomies in children with cerebral palsy).

[Dealing with early complications in unicondylar knee arthroplasty-what works, what does not?] / Umgang mit Frühkomplikationen in der unikondylären Knieprothetik ­ Was funktioniert, was nicht?

Complications in the early postoperative period following the implantation of a unicondylar knee arthroplasty (UKA) are both rare and rarely described in the literature. Often, only small case series or individual case reports are available. In this article, the most common complications of periprosthetic infection, periprosthetic tibial fracture, inlay dislocation and intra-articular cement residue in (loose bone cement body) are described and recommendations for conservative and surgical treatment are presented, including case examples. Ideally, surgical errors or an infection should be recognized at an early stage and revised as soon as possible.

Robotic-assisted total knee arthroplasty results in decreased incidence of anterior femoral notching compared to posterior referenced instrumented total knee arthroplasty.

OBJECTIVE: Periprosthetic fracture (PPF) is an uncommon but devastating complication after total knee arthroplasty (TKA). Anterior femoral notching (AFN) is one of a perioperative risk factor for PPF. The main purpose of this study was to compare between the rates of anterior femoral notching (AFN) and supracondylar periprosthetic femoral fracture (sPPF) of manual TKA and robotic arm-assisted TKA (RATKA). Meanwhile, blood loss, transfusion rates, inflammatory responses, complications, early clinical and radiological outcomes were also assessed. METHODS: This retrospective study included 330 patients (133 RATKA and 197 manual TKA). Differences in risks of inflammatory, blood loss, complications (periprosthetic fracture and periprosthetic joint infection), pre-operative and post-operative distal lateral femoral angle (LDFA), distal femoral width (DFW), prosthesis-distal femoral width (PDFW) ratio, AFN, femoral component flexion angle (FCFA), peri-operative and post-operative functional outcomes between the RATKA and manual TKA groups were compared. RESULTS: The operation time and postoperative CRP level in the RATKA group was significantly longer and higher than that in the manual TKA group (p < .001). However, there was no significant difference in postoperative WBC level (p = .217), hemoglobin loss (p = .362), postoperative drainage (p = .836), and periprosthetic fracture (p = 1.000). There was no significant difference in LDFA (p > .05), DFW(p = .834), PDFW ratio (p = .089) and FCFA (p = .315) between the two groups, but the rate of AFN in the RATKA group was significantly lower than that in the manual TKA group (p < .05). There was no significant difference in ROM between the two groups on POD3, POD 90 and 1 year (p < .05), but the FJS-12 score in the RATKA group was higher than that in the manual TKA group on 1 year (p = .001). CONCLUSION: Robotic-assisted total knee arthroplasty can decrease the incidence of anterior femoral notching compared to posterior referenced instrumented total knee arthroplasty.

Optimizing periprosthetic fracture management and in-hospital outcome: insights from the PIPPAS multicentric study of 1387 cases in Spain.

BACKGROUND: The incidence of all periprosthetic fractures (PPF), which require complex surgical treatment associated with high morbidity and mortality, is predicted to increase. The evolving surgical management has created a knowledge gap regarding its impact on immediate outcomes. This study aimed to describe current management strategies for PPF and their repercussions for in-hospital outcomes as well as to evaluate their implications for the community. METHODS: PIPPAS (Peri-Implant PeriProsthetic Survival Analysis) was a prospective multicentre observational study of 1387 PPF performed during 2021. Descriptive statistics summarized the epidemiology, fracture characteristics, management, and immediate outcomes. A mixed-effects logistic regression model was employed to evaluate potential predictors of in-hospital mortality, complications, discharge status, and weight-bearing restrictions. RESULTS: The study encompassed 32 (2.3%) shoulder, 4 (0.3%) elbow, 751 (54.1%) hip, 590 (42.5%) knee, and 10 (0.7%) ankle PPF. Patients were older (median 84 years, IQR 77-89), frail [median clinical frailty scale (CFS) 5, IQR 3-6], presented at least one comorbidity [median Charlson comorbidity index (CCI) 5, IQR 4-7], were community dwelling (81.8%), and had outdoor ambulation ability (65.6%). Femoral knee PPF were most frequently associated with uncemented femoral components, while femoral hip PPF occurred equally in cemented and uncemented stems. Patients were managed surgically (82%), with co-management (73.9%), through open approaches (85.9%) after almost 4 days (IQR, 51.9-153.6 h), with prosthesis revision performed in 33.8% of femoral hip PPF and 6.5% of femoral knee PPF. For half of the patients, the discharge instructions mandated weight-bearing restrictions. In-hospital mortality rates were 5.2% for all PPF and 6.2% for femoral hip PPF. Frailty, age > 84 years, mild cognitive impairment, CFS > 3, CCI > 3, and non-geriatric involvement were candidate predictors for in-hospital mortality, medical complications, and discharge to a nursing care facility. Management involving revision arthroplasty by experienced surgeons favoured full weight-bearing, while an open surgical approach favoured weight-bearing restrictions. CONCLUSIONS: Current arthroplasty fixation check and revision rates deviate from established guidelines, yet full weight-bearing is favoured. A surgical delay of over 100 h and a lack of geriatric co-management were related to in-hospital mortality and medical complications. This study recommends judicious hypoaggressive approaches. Addressing complications and individualizing the surgical strategy can lead to enhanced functional outcomes, alleviating the economic and social burdens upon hospital discharge. Level of Evidence Level IV case series. TRIAL REGISTRATION: registered at ClinicalTrials.gov (NCT04663893), protocol ID: PI 20-2041.

Femoral Head Core Decompressions: Characterization of Subsequent Conversion to Total Hip Arthroplasty and Related Complications.

BACKGROUND: Core decompression is a minimally invasive joint-preserving approach for early-stage osteonecrosis. The rate at which core decompression patients require total hip arthroplasty (THA) and rates of perioperative adverse outcomes have not been well-characterized. METHODS: Adult patients undergoing core decompression and/or THA with osteonecrosis of the femoral head were identified from the 2015 to 2021 Q3 PearlDiver M157 database. Those undergoing THA without or with antecedent core decompression were identified and matched 4:1 on age, sex, and Elixhauser Comorbidity Index. Postoperative 90-day adverse events were compared with multivariable analysis. Five-year rates of revision, dislocation, and periprosthetic fracture were compared by the Kaplan-Meier curve and log-rank tests. RESULTS: Core decompressions were identified for 3,025 patients of whom 387 (12.8%) went on to THA within 5 years (64% within the first year). The median time from initial core decompression to THA was 252 days. For THA, 26,209 adults were identified and 387 had prior core decompression. After matching, there were 1,320 without core decompression and 339 with core decompression. No statistically significant differences were observed in 90-day postoperative adverse events or 5-year rates of revision, dislocation, or periprosthetic fracture. CONCLUSION: Core decompression may be an option for patients with osteonecrosis and does not seem to affect THA outcomes if required later.

Experimental periprosthetic fractures with collarless polished tapered cemented stems.

PURPOSE: After cemented total hip arthroplasty, the risk of periprosthetic fracture (PPF) of taper-slip stems is higher than that of composite-beam stems. We aimed to assess the conditions resulting in PPFs of taper-slip stems using a falling weight. METHODS: Taper-slip stems were fixed to five types of simulated bone models using bone cement, and the fractures were evaluated by dropping stainless-steel weights from a predetermined height onto the heads. The periprosthetic fracture height in 50% of the bone models (PPFH50) was calculated using the staircase method. RESULTS: For the fixation with 0° of flexion, the values for PPFH50 were 61 ± 11, 60 ± 13, above 110, 108 ± 49, and 78 ± 12 cm for the cobalt-chromium-molybdenum alloy, stainless steel alloy (SUS), titanium alloy (Ti), smooth surface, and thick cement mantle models, respectively; for the fixation with 10° of flexion (considering flexure), the PPFH50 values were 77 ± 5, 85 ± 9, 90 ± 2, 89 ± 5, and 81 ± 11 cm, respectively. The fracture rates of the polished-surface stems were 78.6 and 35.7% at the proximal and distal sites, respectively (p < 0.05); the fracture rates of the smooth-surface stems were 14.2 and 100%, respectively (p < 0.05). CONCLUSION: The impact tests demonstrated that the conditions that were less likely to cause PPFs were use of Ti, a smooth surface, a thick cement mantle, and probably, use of SUS.

Age as a Risk Factor for Intraoperative Periprosthetic Femoral Fractures in Cementless Hip Hemiarthroplasty for Femoral Neck Fractures: A Retrospective Analysis.

Background: Understanding the risk factors and outcomes of intraoperative periprosthetic femoral fractures (IPFF) during hip arthroplasty is crucial for appropriate perioperative management. Previous studies have identified risk factors for IPFF in total hip arthroplasty patients, but data for hip hemiarthroplasty (HA) is lacking. The aim of this study was to determine the age associated with increased rates of IPFF in patients undergoing HA. Methods: We retrospectively reviewed patients aged 65 years and above who underwent a cementless HA for a displaced femoral neck fracture and had a minimum of 1-year follow-up. Patients were stratified into five age groups (65-79, 80-84, 85-89, 90-94, and ≥ 95 years) and further divided into two subgroups (under 95 years and 95 years or older). The presence, location, and treatment of IPFF, as well as the effect of IPFF on the postoperative weight-bearing status, were compared between groups. A multivariate logistic regression was also performed. A total of 1,669 met the inclusion criteria and were included in the study. Results: The rates of IPFF were significantly higher for patients 95 years or older (p = 0.030). However, fracture location (greater trochanter fractures, p = 0.839; calcar fractures, p = 0.394; and femoral shaft fractures p = 0.110), intraoperative treatment (p = 0.424), and postoperative weight-bearing status (p = 0.229) were similar between the groups. While mortality and nonorthopedic-related readmissions were significantly higher for patients 95 years or older, orthopedic-related readmissions (p = 0.148) and revisions at the latest follow-up (p = 0.253) were comparable between groups. In a regression analysis, age over 95 years (odds ratio, 2.049; p = 0.049) and body mass index (odds ratio, 0.935; p = 0.016) were independently associated with IPFF. Conclusions: The findings of this study suggest that age over 95 years is a significant, independent risk factor for IPFF in patients undergoing cementless HA. Although we were unable to show an impact on perioperative outcomes and orthopedic complications, when operating on patients 95 years or older, surgeons should be aware of the increased risk of IPFF and consider the use of stem designs and fixation types associated with decreased IPFF rates.

Mid-term results of total hip arthroplasty with anatomical ultra-short cementless stem in patients with developmental dysplasia of the hip Crowe type II.

The aim of this study was to present the mid-term results of ultra-short cementless stem total hip arthroplasty (THA) in patients with Crowe type II developmental dysplasia of the hip. The study consists of 68 patients (75 THAs) with a Proxima stem implanted between 2006 and 2015. The clinical results include Harris Hip Scores. Radiological follow-up reports on stem migration, bony trabecular development and radiolucent lines. Kaplan-Meier survival analysis was performed. The mean age of patients was 48.4 years, with a mean follow-up 114 months. The average Harris Hip Score improved significantly from 45.1 preoperatively to 97.6 at the final evaluation (p < 0.001). Stem migration was observed in five hips (in all of them up to the 6th postoperative month, without any further progression of migration or radiological loosening). Bony trabecular development was detected in modified Gruen zones (1, 2, 4, 6, 7 for Proxima stem): in zone 1 (0%), 2 (49.3.0%), 4 (38.7%), 6 (82.7%), 7 (0%). Radiolucent lines were observed around one cup (DeLee and Charnley zone I) and three stems (none was loose, all three with fibrous stable fixation). Complications were found in three hips (4.0%): intraoperative periprosthetic femoral fracture (threated with cerclage wire) in two hips and squeezing hip in one patient (with perioperative ceramic inlay breakage and exchange). No hip was revised. The implant survival was 100.0% both clinically and radiologically. Observations in the mean follow-up of 114 months show that the results (clinical and radiological) of the Proxima stem in patients with Crowe type II DDH are promising.

Analysis of complications in 97 periprosthetic Vancouver B2 fractures treated either by internal fixation or revision arthroplasty.

INTRODUCTION: The treatment of Vancouver B2 periprosthetic fractures after hip arthroplasty is still a matter of debate. Revision Arthroplasty (RA) was long thought to be the treatment of choice, however several recent papers suggested that Open Reduction and Internal Fixation (ORIF) is a viable option for selected B2 fractures. Complication rates of 14-26% have been reported following surgical treatment of B2 fractures. No significant difference between RA and ORIF in the complication rates nor in the functional outcome was observed. METHOD: We conducted a retrospective analysis of 97 consecutive Vancouver B2 fractures treated according to the algorithm at our institution from 2007 to 2020 and recorded complications and patient specific data. RESULT: From the 97 patient, 45 fractures were treated with RA while 52 fractures were treated with ORIF. Thirteen patients in the RA group had a complication that needed revision (28%) and 11 patients in the ORIF group needed revision (21%). There was no significant difference between complication rates. The reason for failure in the 13 RA patients were infection (n = 4), stem subsidence (n = 1), refracture after a new fall (n = 3), secondary dislocation of the greater trochanter (n = 1) and dislocation (n = 4). The reason for failure in the 11 ORIF patients that were revised were infection (n = 5), persistent symptomatic stem loosening (n = 3) and refracture (n = 3) after a new fall. CONCLUSION: ORIF can be used to revise cemented and non-cemented shafts in more than half of Vancouver B2 fractures with no difference in complication rates when compared to RA. A periprosthetic fracture around the hip has a 21-28% risk of a re-operation after revision surgery with infection and re-fracture after a new fall being the most frequent cause of re-operation.

Saw-box osteotomy versus reamer-box osteotomy in posterior stabilized total knee arthroplasty: a retrospective study of an average five year follow-up.

PURPOSE: The purpose of this study is to compare the difference of results between two methods of femoral box osteotomy adopted by two designs of posterior stabilized total knee prostheses. PATIENTS AND METHODS: Retrospective analysis of the results of two groups of patients operated upon using two primary PS TKA systems, PFC Sigma (DePuy Synthes, Johnson and Johnson®) and Genesis II prosthesis (Smith and Nephew®), with an average of five year follow-up was done. Group 1 included 152 knees in 121 patients and group 2 included 122 knees in 111 patients. The average follow-up period in both groups was five years. The box osteotomy method depends on bone saw in group 1, and bone reamer in group 2. RESULTS: The KSS score of group 2 was better in the first six months postoperatively. Then, no significant differences were seen in the remaining follow-up visits. The risk of periprosthetic fractures was significantly higher in group 1 (p-value 0.040). Survival analysis showed a significantly shorter time for reoperation in group 1 than in group 2 as described by log-rank test, (p < 0.006). CONCLUSION: The method of box cutting has an impact on the function and longevity of posterior stabilized primary knee implants. The risk of periprosthetic fractures can be reduced by proper patient selection, decreasing the box sizes, and development of more "controlled" box osteotomy instruments.

Changing practice to a new-generation triple-taper collared femoral component reduces periprosthetic fracture rates after primary total hip arthroplasty.

Aims: Periprosthetic femoral fracture (PPF) is a major complication following total hip arthroplasty (THA). Uncemented femoral components are widely preferred in primary THA, but are associated with higher PPF risk than cemented components. Collared components have reduced PPF rates following uncemented primary THA compared to collarless components, while maintaining similar prosthetic designs. The purpose of this study was to analyze PPF rate between collarless and collared component designs in a consecutive cohort of posterior approach THAs performed by two high-volume surgeons. Methods: This retrospective series included 1,888 uncemented primary THAs using the posterior approach performed by two surgeons (PKS, JMV) from January 2016 to December 2022. Both surgeons switched from collarless to collared components in mid-2020, which was the only change in surgical practice. Data related to component design, PPF rate, and requirement for revision surgery were collected. A total of 1,123 patients (59.5%) received a collarless femoral component and 765 (40.5%) received a collared component. PPFs were identified using medical records and radiological imaging. Fracture rates between collared and collarless components were analyzed. Power analysis confirmed 80% power of the sample to detect a significant difference in PPF rates, and a Fisher's exact test was performed to determine an association between collared and collarless component use on PPF rates. Results: Overall, 17 PPFs occurred (0.9%). There were 16 fractures out of 1,123 collarless femoral components (1.42%) and one fracture out of 765 collared components (0.13%; p = 0.002). The majority of fractures (n = 14; 82.4%) occurred within 90 days of primary THA. There were ten reoperations for PPF with collarless components (0.89%) and one reoperation with a collared component (0.13%; p = 0.034). Conclusion: Collared femoral components were associated with significant decreases in PPF rate and reoperation rate for PPF compared to collarless components in uncemented primary THA. Future studies should investigate whether new-generation collared components reduce PPF rates with longer-term follow-up.

Low rate of periprosthetic femoral fracture with the Hueter anterior approach using stems cemented according to the 'French paradox'.

Aims: The aim of this retrospective study was to assess the incidence of early periprosthetic femoral fracture (PFF) associated with Charnley-Kerboull (CK) femoral components cemented according to the 'French paradox' principles through the Hueter anterior approach (HAA) in patients older than 70 years. Methods: From a prospectively collected database, all short CK femoral components implanted consecutively from January 2018 to May 2022 through the HAA in patients older than 70 years were included. Exclusion criteria were age below 70 years, use of cementless femoral component, and approaches other than the HAA. A total of 416 short CK prostheses used by 25 surgeons with various levels of experience were included. All patients had a minimum of one-year follow-up, with a mean of 2.6 years (SD 1.1). The mean age was 77.4 years (70 to 95) and the mean BMI was 25.3 kg/m2 (18.4 to 43). Femoral anatomy was classified according to Dorr. The measured parameters included canal flare index, morphological cortical index, canal-calcar ratio, ilium-ischial ratio, and anterior superior iliac spine to greater trochanter (GT) distance. Results: Among the 416 THAs, two PFFs (0.48% (95% confidence interval 0.13 to 1.74)) were observed, including one Vancouver type B2 fracture 24 days postoperatively and one intraoperative Vancouver type B1 fracture. Valgus malalignment and higher canal bone ratio were found to be associated with PFF. Conclusion: This study demonstrated that short CK femoral components cemented according to the French paradox were associated with a low rate of early PFF (0.48%) in patients aged over 70 years. Longer follow-up is warranted to further evaluate the rate of fracture that may occur during the bone remodelling process and with time.

Immediate weightbearing is safe after revision total hip arthroplasty for Vancouver B2/B3 periprosthetic femur fractures.

INTRODUCTION: Modular fluted, tapered stems provide a reliable treatment for Vancouver B2/B3 fractures. Historically, these patients had weightbearing restrictions postoperatively. Although full immediate postoperative weightbearing may provide benefits in this patient population, stem subsidence is a concern. QUESTIONS/PURPOSES: The objective of this study was to investigate the effect of post-operative weight-bearing status on stem subsidence in patients treated with modular tapered stems for Vancouver B2 and B3 periprosthetic fractures. We sought to answer two questions: (1) Does full immediate postoperative weightbearing after revision total hip arthroplasty for periprosthetic femur fracture lead to increased stem subsidence compared to protected weightbearing? (2) Is there a mortality difference between these two groups of patients with different weightbearing restrictions? METHODS: From 2009 to 2015 all patients who underwent revision for Vancouver B2/B3 fractures were made non-weightbearing (NWB) for six weeks postoperatively. After 2015, immediate weightbearing as tolerated (WBAT) was allowed postoperatively. We compared stem subsidence between immediate postoperative and final radiographs. Additionally, we performed a Kaplan-Meijer analysis with one-year mortality as an endpoint. RESULTS: The final cohort included forty-seven patients with an average follow-up of 254 days. The average stem subsidence was 1.0 mm (95 % CI, 0.5-1.5 mm) in the NWB cohort and 0.3 mm (95 % CI, 0-0.7 mm) in the WBAT cohort (P = 0.10). In our survivorship analysis, we noted no deaths in the WBAT cohort compared to 17 % mortality in the NWB cohort at the one-year timepoint. CONCLUSION: Allowing patients to weight bear immediately after revision does not increase stem subsidence. Further studies are needed to determine whether early weightbearing provides a mortality benefit.