Background:
High tibial osteotomy (HTO) and distal femoral osteotomy (DFO) are well-recognized treatments to address varus and valgus malalignment, respectively, in the setting of symptomatic ...unicompartmental arthritis of the tibiofemoral joint. The existing literature is limited in its ability to characterize complications after HTO or DFO procedures.
Purpose:
The objective of this study was to determine the rate of early (≤90 days) postoperative complications and associated variables from the 15-year experience of a single academic institution.
Study Design:
Case series; Level of evidence, 4.
Methods:
Patients treated at a single academic institution between 2008 and 2022 who underwent HTO or DFO procedures were identified. All patients with minimum 90-day follow-up were considered for inclusion in the study. Exclusion criteria were inadequate follow-up, unavailable medical records, age <14 years, and revision osteotomy. Patient demographic characteristics, surgical history, and concomitant procedures were identified, and risk factor analysis was performed to identify variables associated with early postoperative complications. All intraoperative complications were recorded.
Results:
A total of 243 knees in 232 patients met eligibility and were included in the final analysis. Three intraoperative complications (1.2%) involving fracture extension of the osteotomy occurred. There were 127 early postoperative complications (121 surgical, 6 medical) in 102 knees (68 with HTO and 34 with DFO). Medical complications included pulmonary embolus in 3 patients (1.2%), urinary tract infection in 2 patients (0.8%), and postoperative ileus requiring prolonged hospitalization in 1 patient (0.4%). The most common complications were stiffness requiring a non–standard of care intervention (17.7%), superficial wound infection or wound dehiscence (13.2%), and hemarthrosis or effusion requiring aspiration (6.6%). The rate of deep infection requiring irrigation and debridement was 4.1%. Variables associated with early postoperative complications included smoking (odds ratio OR, 3.05; 95% CI, 1.34-6.94; P = .008), concomitant chondroplasty and/or loose body removal (OR, 2.55; 95% CI, 1.50-4.33; P = .001), and concomitant ligament reconstruction (OR, 3.97; 95% CI, 1.37-11.53; P = .011).
Conclusion:
These 15-year data revealed a low rate of intraoperative complications (1.2%) and a relatively high rate of early (≤90 days) postoperative complications (42.0%) after an HTO or DFO procedure. Surgeons should be aware of the increased postoperative complications associated with smoking, concomitant chondroplasty, and concomitant ligament reconstruction and should use this information to counsel patients regarding appropriate expectations in the postoperative period.
Background
Dome-shaped supramalleolar osteotomies are a well-established treatment option for correcting ankle deformity. However, the procedure remains technically demanding and is limited by a ...two-dimensional (2D) radiographic planning of a three-dimensional (3D) deformity. Therefore, we implemented a weight-bearing CT (WBCT) to plan a 3D deformity correction using patient-specific guides.
Methods
A 3D-guided dome-shaped supramalleolar osteotomy was performed to correct ankle varus deformity in a case series of five patients with a mean age of 53.8 years (range 47–58). WBCT images were obtained to generate 3D models, which enabled a deformity correction using patient-specific guides. These technical steps are outlined and associated with a retrospective analysis of the clinical outcome using the EFAS score, Foot and Ankle Outcome Score (FAOS) and visual analog pain scale (VAS). Radiographic assessment was performed using the tibial anterior surface angle (TAS), tibiotalar angle (TTS), talar tilt angle (TTA), hindfoot angle (HA), tibial lateral surface angle (TLS) and tibial rotation angle (TRA).
Results
The mean follow-up was 40.8 months (range 8–65) and all patients showed improvements in the EFAS score, FAOS and VAS (
p
< 0.05). A 3-month postoperative WBCT confirmed healing of the osteotomy site and radiographic improvement of the TAS, TTS and HA (
p
< 0.05), but the TTA and TRA did not change significantly (
p
> 0.05).
Conclusion
Dome-shaped supramalleolar osteotomies using 3D-printed guides designed on WBCT are a valuable option in correcting ankle varus deformity and have the potential to mitigate the technical drawbacks of free-hand osteotomies.
Level of evidence
Level 5 case series.
Osteoarthritis (OA) of the knee, in most instances primarily, affects medial compartment of knee. Combining Osteochondral Autologous Transfer System (OATS) with Medial Open-Wedge High Tibial ...Osteotomy (MOWHTO) may represent an integrated approach to sustaining long-term knee functionality in OA patients.
From 2009 to 2016, combined OATS and MOWHTO was performed in 66 knees of 63 patients with medial compartment knee OA. Cartilage regeneration was assessed by 2nd look arthroscopy and Knee function was assessed by knee society scoring (KSS) pre-operatively and post-operatively. The survival rate of MOWHTO plus OATS was assessed. Failure is characterized by the need to convert into total knee replacement.
The KSS knee score (from 48.3 to 90.4) and function score (from 42.6 to 88.7) showed a statistically significant improvement (p-value of <0.0001) at a mean follow-up period of 9.49 years. Second look arthroscopy done at the time of implant removal showed 100 % cartilage regeneration with even hyaline cartilage regeneration in 49 out of 57 knees assessed and partial regeneration in 8 knees. The Kaplan Meier survivorship analysis was 96.7 % at the mean 9.49 years after surgery. Only 2 patients needed TKA conversion in follow-up.
Combining OATs and valgus MOWHTO provides good option to successfully manage patients of OA and varus malalignment. This resulted in significant improvement in knee function, lowering pain intensity, good cartilage regeneration, and a high survivorship rate for 10 years postoperatively.
Background:
Recent evidence questions the role of medial opening wedge high tibial osteotomy (mowHTO) in the correction of femoral-based varus malalignment because of the potential creation of an ...oblique knee joint line. However, the clinical effectiveness of alternatively performing an isolated lateral closing wedge distal femoral osteotomy (lcwDFO), in which the mechanical unloading effect in knee flexion may be limited, is yet to be confirmed.
Purpose/Hypothesis:
The purpose of this article was to compare clinical outcomes between patients undergoing varus correction via isolated lcwDFO or mowHTO, performed according to the location of the deformity, in a cohort matched for confounding variables. It was hypothesized that results from undergoing isolated lcwDFO for symptomatic varus malalignment would not significantly differ from the results after mowHTO.
Study Design:
Cohort study; Level of evidence, 3.
Methods:
Consecutive patients who underwent isolated mowHTO or lcwDFO according to a tibial- or femoral-based symptomatic varus deformity between January 2010 and October 2019 were enrolled. Confounding factors, including age at surgery, sex, body mass index, preoperative femorotibial axis, and postoperative follow-up, were matched using propensity score matching. The International Knee Documentation Committee (IKDC) Subjective Knee Form, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Lysholm score, Tegner Activity Scale, and visual analog scale (VAS) for pain were collected preoperatively and at a minimum of 24 months postoperatively.
Results:
Of 535 knees assessed for eligibility, 50 knees (n = 50 patients, n = 25 per group) were selected by propensity score matching. Compared with preoperatively, both the mowHTO group (IKDC, 55.1 ± 16.5 vs 71.3 ± 14.7, P = .002; WOMAC, 22.0 ± 18.0 vs 9.6 ± 10.8, P < .001; Lysholm, 55.2 ± 23.1 vs 80.7 ± 16, P < .001; VAS, 4.1 ± 2.4 vs 1.6 ± 1.8, P < .001) and the lcwDFO group (IKDC, 49.4 ± 14.6 vs 66 ± 20.1, P = .003; WOMAC, 25.2 ± 17.0 vs 12.9 ± 17.6, P = .003; Lysholm, 46.5 ± 15.6 vs 65.4 ± 28.7, P = .011; VAS, 4.5 ± 2.2 vs 2.6 ± 2.5, P = .001) had significantly improved at follow-up (80 ± 20 vs 81 ± 43 months). There were no significant differences between the groups at baseline, at final follow-up, or in the amount of clinical improvement in any of the outcome parameters (P > .05; respectively).
Conclusion:
Performing both mowHTO or lcwDFO yields significant improvement in clinical outcomes if performed at the location of the deformity of varus malalignment. These findings confirm the clinical effectiveness of performing an isolated lcwDFO in femoral-based varus malalignment, which is comparable with that of mowHTO in the correction of varus malalignment.
Varus position of cementless stems is a common malalignment in total hip arthroplasty. Clinical studies have reported a low rate of aseptic loosening but an increased risk for thigh pain. This in ...vitro study aimed to evaluate these clinical observations from a biomechanical perspective.
A conventional cementless stem (CLS Spotorno) was implanted in a regular, straight (size 13.75) as well as in a varus position (size 11.25) in 6 composite femora (Sawbones), respectively. Primary stability was assessed by recording 3-dimensional micromotions under dynamic load bearing conditions and stress shielding was evaluated by registering the surface strain before and after stem insertion.
Primary stability for stems in varus malposition revealed significantly lower micromotions (p < 0.05) for most regions compared to stems in neutral position. The greatest difference was observed at the tip of the stem where the straight aligned implants exceeded the critical upper limit for osseous integration of 150 μm. The surface strains for the varus aligned stems revealed a higher load transmission to the femur, resulting in a clearly altered strain distribution.
This biomechanical study confirms the clinical findings of a good primary stability of cementless stems in a varus malposition, but impressively demonstrates the altered load transmission with the risk for postoperative thigh pain.
•Biomechanical differences of hip stems in normal straight and varus position.•Comparison of 3-dimensional micromotions and surface strain distributions•Varus position resulted in lower micromotions.•Varus aligned stems clearly altered strain distribution.
Purpose
This study indicated the outcomes of three surgical techniques for the treatment of symptomatic unicompartmental knee osteoarthritis (UKOA) with varus malalignment in younger, active ...patients: distal femoral osteotomy (DFO), double-level osteotomy (DLO) and high tibial osteotomy (HTO). The outcomes measured included the return to sport, sport activity and functional scores.
Methods
A total of 103 patients (19 DFO, 43 DLO, 41 HTO) were enrolled in the study and were divided into three groups based on their oriented deformity, each undergoing one of the three surgical techniques. All patients underwent pre- and post-operative evaluations including X-rays, physical exams and functional assessments.
Results
All three surgical techniques were effective in treating UKOA with constitutional malalignment. The average time to return to sport was similar among the three groups (DFO: 6.4 ± 0.3 5.8–7 months, DLO: 4.9 ± 0.2 4.5–5.3 months, HTO: 5.6 ± 0.2 5.2–6 months). The sport activity and functional scores improved significantly for all three groups, with no significant differences observed among the groups.
Conclusion
Various knee osteotomy procedures, DFO, DLO, and HTO, result in high RTS rates and quick RTS times with satisfactory functional scores. Despite pre- to post-operative improvements in sport activities following DFO and DLO, pre-symptom levels were not reached following all evaluated procedures.
Level of evidence
Retrospective case–control study, Level III.
Varus malalignment combined with an increased posterior tibial slope (PTS) in the ACL deficient knee is a frequent pathology; yet, treatment for this condition remains challenging. The presented ...biplanar osteotomy technique allows to simultaneously address both components of malalignment in a single step. A detailed preoperative planning is best achieved by means of a digital planning software and constant intraoperative imaging is performed to verify the correction angle. A bony wedge is resected along with the extension osteotomy according to the preoperative planning and the medial-opening tibial osteotomy site is filled with bone allograft. Two bicortical lag screws are placed in anterior-posterior direction to secure the extension osteotomy, whereas a plate fixation is used for the medial-open osteotomy.
The understanding of the stresses and strains and their dependence on loading direction caused by an axial deformity is very important for understanding the mechanism of femural neck fractures. The ...hypothesis of this study is that lower limb malalignment is correlated with a substantial stress variation on the upper end of the femur. The purpose of this biomechanical trial using the finite element method is to determine the effect of the loading direction on the proximal femur regarding the malalignment of the lower limb, and also enlighten the relation between the lower limb alignment and the risk of a femoral neck fracture.
Ten segmentations of CT scans were considered. An axial compression load was applied to the femoral head to digitally simulate the physiological configuration in neutral position as well as in different axial positions in varus/valgus alignment.
The stress at the proximal femur changes as the varus _valgus angle does. It can be observed the smaller absolute stress at angle 10° (valgus) and the higher absolute stress at angle -10° (varus). The mean maximum von Mises stress value was 14.1 (SD=±3.48) MPa for 0°, while the mean maximum von Mises stress value was 17.96 MPa (SD=4.87) for -10° in varus. The fracture risk indicator of the proximal femoral epiphyses changes inversely with angle direction. The FRI was the highest at -10° and the lowest at 10°.
Based on the biomechanical findings and the fracture risk indicator determined in this preliminary study, varus malalignment increases the risk of femoral neck fracture. Consideration of other parameters such as bone mineral density and morphological parameters should also help to plan preventive medical strategy in the elderly.
Purpose
The first purpose of this study was to introduce an individualized, pathology-based approach for the amount of axis correction in valgus high tibial osteotomy (HTO), in which the ...weight-bearing line (WBL) is transferred in one of three adjacent 5 %-areas of the transverse diameter of the tibial plateau. The second purpose was to define the corresponding mechanical femorotibial angle (mFTA) for the margins of each 5 %-area.
Methods
Reported indications for valgus HTO were assorted to one of three groups, based on the underlying pathology and expected accompanying degree of osteoarthritis. Three adjacent 5 %-areas on the tibial plateau were defined, ranging from the 50 % to 65 % coordinate. The medial border of the tibial plateau was defined as 0 % and the lateral border was defined as 100 %. To define the corresponding mFTA, valgus HTO was simulated in 69 patients using commercial available planning software (mediCAD®, Hectec GmbH, Germany). The corresponding mFTA was recorded at four different positions (50 %, 55 %, 60 %, and 65 %).
Results
Within the purposed approach, the WBL is aimed in one of three 5 %-areas (50–55 %, 55–60 %, and 60–65 %) of the transverse diameter of the tibial plateau, according to the underlying pathology. Based on the findings of simulated HTO, the mean mFTA was 0.3° ± 0.2° at the 50 % position, 1.3° ± 0.2° at the 55 % position, 2.4° ± 0.3° at the 60 % position, and 3.4° ± 0.3° at the 65 % position. The mean difference of the mFTA between each adjacent valgus position was 1.1° ± 0.1°.
Conclusion
The present paper introduces an individualized approach to adopt the degree of valgus correction in dependence of the underlying pathology. The area of interest on the tibial plateau lies in between the 50 % and 65 % coordinate on the tibial plateau, or in between a mean mFTA of 0.3° and 3.4° of valgus, respectively. Differences of the resulting mFTA between each area are small, and therefore a precise surgical technique is mandatory.
•Our findings revealed that in vivo oxidation is a main contributing factor to the failure of implants, but not varus malalignment.•Highest surface roughness on the medial part for both polethylene ...tibial inserts was due to varus malalignment knee.•Our data demonstrated a strong association between the change of molecular weight and surface damage mode formation delamination and crater with oxidation.
Failure analysis on a retrieved ultra-high molecular weight (UHMWPE) knee tibial inserts of bilateral total knee replacement (TKR) was performed due to aseptic loosening detected after 16 years (left) and 12 years (right) in vivo services. Despite long implantation time, the effect of varus malalignment present on a 71 years old female patient (body mass index, 35.1) with a non-active lifestyle will be considered as a factor towards the TKR failure. We, therefore, determined whether implant malalignment was associated with increased surface damages in both retrieved tibial inserts. Surface damage morphology was assessed using a 3D laser microscope and Scanning Electron Microscope (SEM). ATR-Fourier Transform Infra-Red (ATR-FTIR), Differential Scanning Calorimetry (DSC) and Gel-Permeation Chromatography (GPC) were used to measure changes of chemical and physical properties of retrieved inserts. Results show left-16 years insert possesses more severe wear degradation (crater and cracks) compare to wear on right-12 years insert (delamination, multidirectional scratches, and ripple). The surface roughness on the medial compartment seems to be higher than the lateral side for both inserts which can be affected by uneven load distribution contribute by the varus deformity. Higher crystallinity of left-16 years insert (66.99%) compare to right-12 years insert (56.52%) were an indicator of major mechanical changes happen on left insert which was contributed by oxidation with respect to implantation time of both inserts. Our findings revealed that in vivo oxidation is a main contributing factor to the failure of implants, but not varus malalignment. The material properties in the oxidized layer are significantly altered, including a very substantial reduction in molecular weight displayed by both inserts.
