Alignment in the varus or valgus outlier range of the tibial component, knee, and limb might adversely affect the long-term results of kinematically aligned total knee arthroplasty (TKA) particularly ...when patients are selected without restricting the degree of preoperative varus-valgus and flexion deformity.
A retrospective review of all patients treated in 2007 with a primary TKA determined the 10-year implant survivorship, yearly revision rate, Oxford Knee Score, and WOMAC. All 222 knees (217 patients) were aligned kinematically using patient-specific instrumentation without restricting the degree of preoperative deformity and with the restoration of the native joint lines and limb alignment. Mechanical alignment criteria categorized the alignments of the tibial component, knee, and limb as in-range or in a varus or valgus outlier range.
The implant survivorship (yearly revision rate) was 97.5% (0.3%) for revision for any reason and 98.4% (0.2%) for aseptic failure. The percentage postoperatively aligned in the varus outlier (valgus outlier) range was 78% (0%) for the angle between the tibial component and mechanical axis of the tibia, 31% (5%) for the tibiofemoral angle of the knee according to the criteria by Ritter et al, and 7% (21%) for the hip-knee-ankle angle of the limb according to the criteria by Parratte et al. Patients grouped in the varus outlier range, valgus outlier range, and in-range had similar implant survival and function scores. The 10-year Oxford Knee Score (48 best) and WOMAC (0 best) averaged 43 and 7 points, respectively.
With the limitation that a large case series unlikely represents the full range of preoperative deformities and native alignments, treatment of patients with kinematically aligned TKA with patient-specific instrumentation without restricting the preoperative deformity did not adversely affect the 10-year implant survival, yearly revision rate, and level of function.
Level III, therapeutic study.
We sought to understand the mortality rate of periprosthetic joint infection (PJI) of the hip undergoing 2-stage revision for infection.
Database search, yielding 23 relevant studies, totaled 19,169 ...patients who underwent revision for total hip PJI.
One-year weighted mortality rate was 4.22% after total hip PJI. Five-year mortality was 21.12%. Average age was 65 years. When comparing the national age-adjusted risk of mortality and the reported 1-year mortality risk in this systematic review, the risk of death after total hip PJI is significantly increased (odds ratio 3.58, P < .001).
The mortality rate during total hip revision for infection is high. When counseling a patient regarding complications of this disease, death should be discussed.
Purpose
The present study determined the postoperative phenotypes after unrestricted calipered kinematically aligned (KA) total knee arthroplasty (TKA), whether any phenotypes were associated with ...reoperation, implant revision, and lower outcome scores at 4 years, and whether the proportion of TKAs within each phenotype was comparable to those of the nonarthritic contralateral limb.
Methods
From 1117 consecutive primary TKAs treated by one surgeon with unrestricted calipered KA, an observer identified all patients (
N
= 198) that otherwise had normal paired femora and tibiae on a long-leg CT scanogram. In both legs, the distal femur–mechanical axis angle (FMA), proximal tibia–mechanical axis angle (TMA), and the hip–knee–ankle angle (HKA) were measured. Each alignment angle was assigned to one of Hirschmann’s five FMA, five TMA, and seven HKA phenotype categories.
Results
Three TKAs (1.5%) underwent reoperation for anterior knee pain or patellofemoral instability in the subgroup of patients with the more valgus phenotypes. There were no implant revisions for component loosening, wear, or tibiofemoral instability. The median Forgotten Joint Score (FJS) was similar between phenotypes. The median Oxford Knee Score (OKS) was similar between the TMA and HKA phenotypes and greatest in the most varus FMA phenotype. The phenotype proportions after calipered KA TKA were comparable to the contralateral leg.
Conclusion
Unrestricted calipered KA’s restoration of the wide range of phenotypes did not result in implant revision or poor FJS and OKS scores at a mean follow-up of 4 years. The few reoperated patients had a more valgus setting of the prosthetic trochlea than recommended for mechanical alignment. Designing a femoral component specifically for KA that restores patellofemoral kinematics with all phenotypes, especially the more valgus ones, is a strategy for reducing reoperation risk.
Level of evidence
Therapeutic, Level III
Periprosthetic joint infections (PJIs) are fraught with multiple complications including poor patient-reported outcomes, disability, reinfection, disarticulation, and even death. We sought to perform ...a systematic review asking the question: (1) What is the mortality rate of a PJI of the knee undergoing 2-stage revision for infection? (2) Has this rate improved over time? (3) How does this compare to a normal cohort of individuals?
We performed a database search in MEDLINE/EMBASE, PubMed, and all relevant reference studies using the following keywords: “periprosthetic joint infection,” “mortality rates,” “total knee arthroplasty,” and “outcomes after two stage revision.” Two hundred forty-two relevant studies and citations were identified, and 14 studies were extracted and included in the review.
A total of 20,719 patients underwent 2-stage revision for total knee PJI. Average age was 66 years. Mean mortality percentage reported was 14.4% (1.7%-34.0%) with average follow-up 3.8 years (0.25-9 years). One-year mortality rate was 4.33% (3.14%-5.51%) after total knee PJI with an increase of 3.13% per year mortality thereafter (r = 0.76 0.49, 0.90, P < .001). Five-year mortality was 21.64%. When comparing the national age-adjusted mortality (Actuarial Life Table) and the reported 1-year mortality risk in this meta-analysis, the risk of death after total knee PJI is significantly increased, with an odds ratio of 3.05 (95% confidence interval, 2.69-3.44; P < .001).
The mortality rate after 2-stage total knee revision for infection is very high. When counseling a patient regarding complications of this disease, death should be discussed.
What's New in Sports Medicine Thompson, Kamali A; Shelton, Trevor J; Lee, Cassandra A
Journal of bone and joint surgery. American volume,
2024-Apr-17, 2024-4-17, 20240417, Volume:
106, Issue:
8
Journal Article
Background:
Femoroacetabular impingement (FAI) is often a chronic problem, which can lead to a decrease in mental well-being.
Purpose/Hypothesis:
The purpose of this study was to determine patient ...mental health improvement after hip arthroscopy and if this improvement correlated with improved outcomes. It was hypothesized that patients with low mental health (LMH) status would improve after hip arthroscopy for FAI and that their patient-reported outcomes (PROs) would significantly improve after surgery.
Study Design:
Cohort study; Level of evidence, 3.
Methods:
Patients who underwent hip arthroscopy with labral repair between 2008 and 2015 were included. The minimum follow-up was 2 years. PROs included the modified Harris Hip Score (mHHS), Hip Outcome Score–Activities of Daily Living (HOS-ADL), HOS–Sports (HOS-Sports), and 12-Item Short Form Health Survey (SF-12). The minimal clinically important difference and Patient Acceptable Symptom State (PASS) were determined for HOS-ADL, HOS-Sports, and the mHHS based on previously published studies. Patients who scored <46.5 on the SF-12 Mental Component Summary (MCS) were in the LMH group, and those who scored ≥46.5 were in the high mental health (HMH) group.
Results:
In total, 120 (21%) of the 566 patients were in the LMH group and 446 (79%) patients were in the HMH group preoperatively. There was no difference in age or sex between groups. Patients in the LMH group had lower mHHS, HOS-ADL, and HOS-Sports at the mean 4-year follow-up and were less likely to reach PASS for the scores. Postoperatively, 84% (478/566) of the entire group was in the HMH group. A total of 88 (73%) of the LMH group improved to HMH. A multiple linear regression model for change in MCS identified independent predictors of changes in preoperative MCS to be LMH group preoperatively, change in HOS-Sports, and change in mHHS (r2 = 0.4; P < .001).
Conclusion:
HMH was achieved in 84% of the patients after hip arthroscopy for FAI. Improvement in MCS was correlated with function and activity, as indicated by a significant correlation with HOS-ADL and HOS-Sports. A small percentage of patients did see a decline in their MCS score. This study showed that patients with LMH scores before hip arthroscopy for FAI can improve to normal/high mental health, and this correlated with higher PROs.
Four mechanical alignment force targets are used to predict early patient-reported outcomes and/or to indicate a balanced TKA. For surgeons who use kinematic alignment, there are no reported force ...targets. To date the usefulness of these mechanical alignment force targets with kinematic alignment has not been reported nor has a specific force target for kinematic alignment been identified.
(1) Does hitting one of four mechanical alignment force targets proposed by Gustke, Jacobs, Meere, and Menghini determine whether a patient with a kinematically aligned TKA had better patient-reported Oxford Knee and WOMAC scores at 6 months? (2) Can a new force target be identified for kinematic alignment that determines whether the patient had a good/excellent Oxford Knee Score of ≥ 34 points (48 best, 0 worst)?
Between July 2017 and November 2017, we performed 148 consecutive primary TKAs of which all were treated with kinematic alignment using 10 caliper measurements and verification checks. A total of 68 of the 148 (46%) TKAs performed during the study period had intraoperative measurements of medial and lateral tibial compartment forces during passive motion with an instrumented tibial insert and were evaluated in this retrospective study. Because the surgeon and surgical team were blinded from the display showing the compartment forces, there was no attempt to hit a mechanical alignment force target when balancing the knee. The Oxford Knee Score and WOMAC score measured patient-reported outcomes at 6 months postoperatively. For each mechanical alignment force target, a Wilcoxon rank-sum test determined whether patients who hit the target had better outcome scores than those who missed. An area under the curve (AUC) analysis tried to identify a new force target for kinematic alignment at full extension and 10°, 30°, 45°, 60°, 75°, and 90° of flexion that predicted whether patients had a good/excellent Oxford Knee Score, defined as a score of ≥ 34 points.
Patients who hit or missed each of the four mechanical alignment force targets did not have higher or lower Oxford Knee Scores and WOMAC scores at 6 months. Using the Gustke force target as a representative example, the Oxford Knee Score of 41 ± 6 and WOMAC score of 13 ± 11 for the 31 patients who hit the target were not different from the Oxford Knee Score of 39 ± 8 (p = 0.436) and WOMAC score of 17 ± 17 (p = 0.463) for the 37 patients who missed the target. The low observed AUCs (from 0.56 to 0.58) at each of these flexion angles failed to identify a new kinematic alignment force target associated with a good/excellent (≥ 34) Oxford Knee Score.
Tibial compartment forces comparable to those reported for the native knee and insufficient sensitivity of the Oxford Knee and WOMAC scores might explain why mechanical alignment force targets were not useful and a force target was not identified for kinematic alignment. Intraoperative sensors may allow surgeons to measure forces very precisely in the operating room, but that level of precision is not called for to achieve a good/excellent result after calipered kinematically aligned TKA, and so its use may simply add expense and time but does not improve the results from the patient's viewpoint.
Level III, therapeutic study.
Purpose
Surgeons performing total knee arthroplasty (TKA) on the osteoarthritic valgus deformity often use a posterior stabilized (PS) and semi-constrained implants to substitute for the release of a ...contracted posterior cruciate ligament (PCL) instead of a cruciate retaining (CR) implant. Calipered kinematic alignment (KA) strives to retain the PCL and use a CR implant. The aim of this study of the windswept deformity was to determine whether the level of implant constraint, outcome scores, and alignment after bilateral calipered KA TKA are different between a pair of knees with a varus and valgus deformity in the same patient.
Methods
A review of a prospectively collected database identified all patients with a windswept deformity treated with bilateral TKA (
n
= 19) out of 2430 consecutive primary TKAs performed between 2014 and 2019. Operative reports determined the level of implant constraint. Patient response to the Forgotten Joint Score (FJS) and Oxford Knee Score (OKS) assessed outcomes at a mean follow-up of 2.3 years. Postoperative alignment was measured on an A-P computer tomographic scanogram of the limb.
Results
CR implants were used in 15 of 19 (79%) valgus deformities and 17 of 19 (89%) of varus deformities (n.s.). No knees required a semi-constrained implant. There was no difference in the median postoperative FJS and OKS (n.s.), and a 1° or less difference in the mean postoperative distal lateral femoral angle (
p
= 0.005) and proximal medial tibial angle (n.s.) between the paired varus and valgus knee deformity.
Conclusion
Based on this small series, surgeons that use calipered KA TKA can expect to use CR implants in most patients with windswept deformity and achieve comparable outcome scores and alignment between the paired varus and valgus deformity.
Level of evidence
IV
Purpose
Floating knee injuries are relatively uncommon injuries. We report the prevalence, location, and severity of heterotopic ossification (HO) around the knee in patients treated with antegrade ...tibial intramedullary nailing and ipsilateral antegrade versus retrograde femoral intramedullary nailing as well as how the severity of HO around the knee affects knee range of motion (ROM).
Methods
From 2004 to 2014, 26 floating knee injuries were included. Radiographs were reviewed to determine presence, location, and severity of HO. Post-operative knee ROM was determined.
Results
A significantly higher prevalence of HO around the knee was detected in the retrograde group (90%) compared to the antegrade group (43%) (
p
= 0.028). There was a trend for more HO into the patellar tendon occurring in 29% of patients in the antegrade group and 74% in the retrograde group (
p
= 0.069). The severity of HO was higher for the retrograde group 1.6 ± 1.0 compared to the antegrade group 0.4 ± 0.5 (
p
= 0.004). There was poor correlation between HO severity and knee ROM.
Conclusions
Treatment of floating knee injuries with a retrograde femoral nail was demonstrated to result in a greater likelihood of developing HO and a greater severity of HO around the knee than if treated with an antegrade femoral nail. However, this increased severity of HO is unlikely to affect ROM.
Level of evidence: III.
The purpose of this study was to determine whether aging imparts a clinically significant effect on the (1) mechanism of graft failure and (2) structural, material, and viscoelastic properties of ...patellar tendon allografts by evaluating these properties in younger donors (≤30 years of age) and older donors (>50 years of age).
A total of 34 younger (≤30 years of age) and 34 older (>50 years of age) nonirradiated, whole bone-tendon-bone allografts were prepared for testing by isolating the central third of the patellar tendon using a double-bladed 10-mm width scalpel under a 10-N load to ensure uniformity of harvest. Bone blocks were potted in polymethylmethacrylate within custom molds. Tendon length and cross-sectional area were measured using an area micrometer. A mechanical loading system was used to precondition the grafts for 100 cycles with a load between 50 N and 250 N (1 Hz). A creep load (500 N) was then applied at a rate of 100 mm/min (10 minutes). Grafts were allowed to recover at 1 N (10 minutes), followed by pull-to-failure at a rate of 100% strain per second. Mechanisms of failure (midsubstance vs avulsion) were noted and the structural, material, and viscoelastic properties calculated and compared between groups.
There were 33 (97%) midsubstance tears in the younger group and 28 (82%) in the older group (P = .034). Younger grafts showed greater ultimate load to failure (1,782 N 1,533, 2,032 vs 1,319 N 1,103, 1,533) (P = .006) and ultimate tensile stress (37.4 MPa 32.4, 42.4 vs 27.5 MPa 22.9, 32.0) (P = .006). There were no significant differences in displacement (P = .595), stiffness (P = .950), strain (P = .783), elastic modulus (P = .114), creep displacement (P = .881), and creep strain (P = .614).
This in vitro study suggests that aging weakens the bone-tendon junction and decreases the ultimate tensile strength of patellar tendon allografts. However, aging did not affect the displacement, strain, stiffness, elastic modulus, creep displacement, or creep strain of patellar tendon allografts.
Surgeons should be aware that patellar tendon allografts from donors >50 years of age have a lower ultimate tensile stress than donors ≤30 years of age.
PDF
