Valgus Malalignment Research Articles

Stress Distribution Patterns of the Femorotibial Joint After Medial Closing-Wedge Distal Femoral Varus Osteotomy: An Evaluation Using Computed Tomography Osteoabsorptiometry

Background: Distal femoral varus osteotomy (DFVO) is an established surgical procedure for addressing valgus malalignment across various knee conditions. However, the effect of DFVO on stress distribution within the femorotibial joint has not been explored through in vivo studies. Purpose: To (1) explore the distribution pattern of subchondral bone density across the proximal tibia in nonarthritic knees without arthritis and in those of patients with valgus knees, (2) assess changes in the pattern of bone density distribution in patients with valgus knees before and after medial closing-wedge (MCW) DFVO, and (3) determine the correlation between leg alignment and changes in bone density distribution. Study Design: Cohort study; Level of evidence, 3. Methods: The authors retrospectively analyzed clinical and radiographic data from 14 patients (14 knees; mean age, 44 years; 3 men, 11 women) treated with MCW-DFVO for lateral compartment osteoarthritis (OA) due to valgus malalignment, alongside a control group of 18 patients (18 knees; mean age, 21 years; 4 men, 14 women) without OA. The distribution patterns of subchondral bone density distribution on the femorotibial articular surface of the tibia were examined both preoperatively and >1 year postoperatively using computed tomography osteoabsorptiometry. Quantitative analyses were conducted on the locations and percentages of the high-density areas (HDAs) on the articular surface. The mean time between surgery and the postoperative radiograph and computed tomography absorptiometry imaging was 13.6 months (range, 11-19 months). The mean length of clinical follow-up was 28.7 months (range, 14-62 months) after surgery. Results: The mean proportion of HDA in the lateral compartment relative to the total HDA (lateral ratio) was significantly greater in the preoperative OA group (58.8%) compared with the control group (41.1%) (P < .001). After MCW-DFVO, the mean lateral ratio in the OA group notably declined to 45.3% (P < .001). The lateral ratio exhibited a significant correlation with the hip-knee-ankle angle in both the control (r = 0.630; P = .011) and OA (r = 0.537; P = .047) groups. Moreover, the alteration in the lateral ratio after MCW-DFVO showed a significant relationship with changes in the hip-knee-ankle angle (r = 0.742; P = .002) and the mechanical lateral distal femoral angle (r = −0.752; P = .002). Within the lateral compartment, HDAs in the 3 lateral regions of the 4 lateral subregions diminished after MCW-DFVO, whereas in the medial compartment, HDAs in the 3 lateral subregions saw an increase. Conclusion: The mean lateral ratio was significantly greater in the preoperative OA group compared with the control group. MCW-DFVO resulted in a redistribution of HDA from the lateral to the medial compartment of the proximal tibial articular surface. The extent of alignment correction after MCW-DFVO was closely linked to the shifts in HDA distribution, reflecting changes in stress distribution.

Isolated in-situ mosaicplasty fixation of unstable knee osteochondritis dissecans in skeletally mature patients; a combined mechanical and biological solution with excellent outcomes and a low re-operation rate

ObjectivesUnstable Osteochondritis dissecans (OCD) of the knee can result in substantial morbidity; the aims of surgical management are to provide stability to the lesion and to stimulate biological healing. The aims of this paper were to review the outcomes of a previously described, but uncommonly used, technique involving isolated mosaicplasty fixation of unstable knee OCD. MethodsA retrospective review of skeletally mature patients treated with in-situ mosaicplasty fixation of unstable OCD of the knee was performed. Two out of thirteen knees also underwent concomitant realignment osteotomy. Post-operative Magnetic Resonance Imaging (MRI) and patient reported outcome measures were reviewed. ResultsTwelve patients (13 knees) were included; there were 5 females and 7 males. The mean age at time of surgery was 22 years (range 16-32). The lesion location was lateral femoral condyle in 7 cases and medial femoral condyle in 6 cases. Follow-up MRI scans confirmed fragment healing in 12 knees (92%). One patient required further surgical intervention for ongoing symptoms and radiological non-union: the patient underwent an off-loading distal femoral osteotomy to correct valgus mal-alignment. ConclusionThis series describes the outcomes following an uncommonly performed, yet reproducible and effective method of fixation of unstable knee OCDs. We believe in-situ mosaicplasty fixation represents an opportunity to provide both mechanical stability and biological augmentation of OCD healing and the series confirms that excellent results can be achieved, with a low re-operation rate. Level of EvidenceLevel IV

Lateral open wedge tibial osteotomy for posttraumatic deformity

Correction of pseudoinstability and tibial malalignment by re-establishment of the pretraumatic tibial axis. Posttraumatic valgus malalignment accompanied by pseudoinstability. Infections, significant inhibition of movement and multidirectional ligament instability. Standard anterolateral approach to the proximal tibial head. Lateral open wedge high tibial osteotomy above (supra) the tibiofibular joint and opening until the pseudoinstability of the lateral collateral ligament is levelled. Partial weight bearing for 4weeks, after radiological control full body weight loading is allowed. Implant removal after full bony consolidation. There is limited evidence in the current literature but the available results show good results in 70% of the cases in long-term follow-up.

Does gait influence biomechanics in a distal femoral osteotomy? An early post operative fracture after DFO above a Tomofix® plate in a multiple sclerosis and low-density bone affected patient: choose a longer plate—a case report

BackgroundDistal femur osteotomies are a well known and valuable treatment option to manage valgus malalignment with unicompartmental arthritis. Early postoperative complications are well known, and risk factors, such as pulmonary diseases, smoke, high dependent functional status, and body mass index, have been studied, but no study is available about osteotomies when gait is abnormal because of neurodegenerative conditions or when mineral density is below the normal rate.Case presentationWe report the case of a 44 year-old female Mediterranean patient who underwent a biplanar distal femur opening wedge osteotomy surgery following a lateral meniscus total removal, which led to the subsequent development of lateral compartment osteoarthritis and pain, despite general comorbidities, such as multiple sclerosis. Additionally, 2 months later a supracondylar femur fracture above the previously applied Tomofix® plate was reported. Fracture was treated by applying a LCP condylar 16 hole (336 mm) plate, a structural fibular graft, and strut fibular graft on the opposite side.ConclusionThe overall aim of this case report is to provide a lesson to surgeons who want to perform a realignment surgery of the lower limb in patients with abnormal gait. Not only mechanical axes are to be considered, but also bone density, patient’s gait, and load force distribution along the bone stock. Emerging literature on three-dimensional cutting guides fails to account for these factors, thus promoting a standardized approach to surgery across all patients. The present case highlights a patient with low bone density and abnormal force distribution resulting from a pathologic neurodegenerative gait. In such cases, treatment decisions must carefully consider the biomechanical vulnerabilities of the native bone and the distribution of vector forces. These conditions must lead the choice toward a longer plate if an osteotomy is indicated, because surgery is more likely to fail.

Good 5-year results and a low redislocation rate using an á la carte treatment algorithm for patellofemoral instability in patients with severe trochlea dysplasia.

Trochlear dysplasia is a major risk factor for recurrent patellar instability, reduced quality of lifeand osteoarthritis of the patellofemoral joint. Patellar instability in patients with trochlear dysplasia can be treated by trochleoplasty, usually in combination with medial patellofemoral ligament reconstruction (MPFL-R). An á la carte treatment algorithm, which also addresses patella alta, lateralisation of the tibial tuberosityand valgus or torsional malalignment when present has been standard in one clinic for treatment of patellar instability patients since 2009, based on the hypothesis that it results in optimal subjective and clinical outcome, normalisation of the lateral trochlea inclination (LTI) angle and a low rate of patellar redislocation. This prospective study reports the 5-year results for consecutive patients with high-grade trochlea dysplasia operated according to the algorithm 2010-2017, evaluated preoperatively and 1, 2and 5 years postoperatively. Clinical information on previous surgery and postoperative patellar stability, range-of-motion (ROM)and subsequent surgery were registered. Subjective outcome was evaluated by four patient-reported outcome measures (PROMs): Kujala, Lysholm, International Knee Documentation Committee and Knee injury and Osteoarthritis Outcome Score. The LTI angle was measured pre- and postoperatively on magnetic resonance imaging scans. There were 131 patients (87 females) with a median age of 22 years (range: 14-38). All had a trochleoplasty and an MPFL-R. Additional procedures (tibial tuberosity medialisation/distalisation and/or femoral/tibial osteotomy) were performed in 52%. All PROM scores improved from preoperatively to 1-year follow-up with further improvement at 2 and 5 years after surgery (p < 0.05). Three patients (2%) had a traumatic patellar dislocation 9, 12and 24 months postoperativelyand 38% underwent subsequent surgery (hardware removal, arthroscopically assisted brisement force, knee arthroscopy). A normalisation of the LTI angle (≥11°) was achieved in 76%. Treatment according to the à la carte algorithm for patients with patellar instability and high-grade trochlear dysplasia resulted in significant clinical and subjective improvement in all PROM scores and a very low redislocation rate (2%) 5years after surgery. Level II.

Ten-year minimal follow-up of lateral opening wedge distal femoral osteotomy for lateral femorotibial osteoarthritis: Good survivorship and high patient satisfaction.

This study aimed (1) to determine complications and survival rates of lateral opening wedge distal femoral osteotomy (LOW-DFO) in the long term, (2) to assess their clinical outcomes in the long term and (3) to identify risk factors of failure. Between 1991 and 2011, 62 LOW-DFOs were performed in the same department. Inclusion criteria were all isolated LOW-DFO performed for isolated lateral tibiofemoral osteoarthritis and valgus malalignment, with a minimum 10-year follow-up. Thirty-eight patients were included, with a mean age of 48 ± 9 years. All patients had clinical and radiological assessments. The survival curves were calculated based on the following endpoints: unicompartmental or total knee arthroplasty. The mean follow-up was 15.2 ± 4.4 [10-29] years. The mean preoperative mechanical FemoroTibial Axis (mFTA) was 188.8° ± 3.2° [184°-197°], primarily due to femur deformity (mean lateral distal femoral axis [LDFA] 83.2° ± 2.8°). Bone union was achieved in 89.5% of patients (n = 34) at a mean delay of 6.5 ± 6.7 months. The complication rate was 26% (five stiffness, one nonunion, three secondary displacements and one deep vein thrombosis). Nine revision surgeries (24%) were recorded. Survival rates at 5 and 10 years were 92.1% and 78.9%, respectively. The mean delay between DFO and total knee arthroplasty (TKA) was 11.6 ± 5.7 [1-27] years. Nineteen patients (50%) were free of TKA at the last follow-up. KSS scores were improved significantly. Return to sports was obtained in 92% of cases (n = 35), with a mean delay of 11 ± 8 months. Seventy-four per cent of patients were satisfied or very satisfied with the surgery. Eighty-four per cent would be willing to undergo the surgery again. Older age (p = 0.032) was a significant risk factor for TKA conversion. LOW-DFO is an efficient procedure to manage lateral knee osteoarthritis in young patients with valgus deformity, with a good survival rate at 10 years and high patient satisfaction. Level III.

Extra-articular Osteotomy for the Management of Intra-articular Tibial Plateau Valgus Malunion.

To report a case series of extra-articular osteotomies for the management of intra-articular tibial plateau malunions and to assess the ability to correct deformity and improve knee range of motion (ROM). . Retrospective case series. Academic, tertiary, referral center. Adult patients with tibial plateau fracture malunion treated with extra-articular osteotomy of the femur and/or tibia between 2014 and 2023. Mechanical axis deviation (MAD), medial proximal tibia angle (MPTA), lateral distal femoral angle (LDFA), and posterior proximal tibia angle (PPTA) correction; knee ROM; and time to weight bearing. There were 7 patients included, 6 (85.7%) were female and 1 (14.3%) were male. The median age was 43.5 years (IQR 38.5-51, range 32-62). Four (57.1%) patients were treated with a high tibial osteotomy (HTO), and 3 (42.9%) patients were treated with an HTO and distal femoral osteotomy. One patient had concomitant supramalleolar osteotomy with HTO to address distal tibia procurvatum and valgus. Four were treated with hexapod frames, and 3 were treated with plates and screws. Median follow-up was 22.5 months (IQR 10.5-107 months, range 7-148 months). Surgical intervention corrected median radiographic measures of valgus malalignment preoperatively relative to postoperative values. This included MAD (42.5 mm-0 mm), valgus angle (12.5 degrees-1.5 degrees), MPTA (95 degrees-88.0°), and LDFA (86.0°-87.3 degrees). Surgical intervention increased maximal knee range of motion preoperatively to postoperatively. Median time to full weight bearing was 81.5 days (IQR 46-57 days, range 41-184 days). Two patients were converted to total knee arthroplasty after 5 and 10 years following HTO with hexapod frame. Extra-articular osteotomy is an effective treatment for addressing intra-articular malunion after tibia plateau fractures. It is effective in correcting the MAD, valgus deformity, MPTA, LDFA, PPTA, and improving knee ROM (measured through knee extension and flexion). Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Relevance of instrumented gait analysis in the prediction of the rebound phenomenon after guided growth intervention

Predictors of rebound after correction of coronal plane deformities using temporary hemiepiphysiodesis (TH) are not well defined. The following research questions were tested: (1) Is the dynamic knee joint load useful to improve rebound prediction accuracy? (2) Does a large initial deformity play a critical role in rebound development? (3) Are BMI and a young age risk factors for rebound? Fifty children and adolescents with idiopathic knee valgus malalignment were included. A deviation of the mechanical femorotibial angle (MFA) of ≥ 3° into valgus between explantation and the one-year follow-up period was chosen to classify a rebound. A rebound was detected in 22 of the 50 patients (44%). Two predictors of rebound were identified: 1. reduced peak lateral knee joint contact force in the first half of the stance phase at the time of explantation (72.7% prediction); 2. minor initial deformity according to the MFA (70.5% prediction). The best prediction (75%) was obtained by including both parameters in the binary logistic regression method. A TH should not be advised in patients with a minor initial deformity of the leg axis. Dynamic knee joint loading using gait analysis and musculoskeletal modeling can be used to determine the optimum time to remove the plates.

Patients aged 55 or older undergoing around the knee osteotomy have a higher rate of deep vein thrombosis but not overall early post-operative complications.

Osteotomies around the knee have been established as an effective method for treating varus or valgus malalignment associated with other knee pathologies in young and middle-aged patients. There is limited literature regarding the risks and complications based on patient age. The purpose of this study is to determine whether age influences as a risk factor for developing intraoperative and early post-operative complications in patients undergoing osteotomies around the knee. A consecutive series of patients over 18 years old who underwent distal femoral osteotomy (DFO) or high tibial osteotomy (HTO) with a minimum follow-up period of 90 days were included. Demographic characteristics, surgical technique, intraoperative and post-operative complications up to 90 days were identified. A statistical comparison based on age younger than 55 years or 55 years and older was conducted to determine if patient age acted as a risk factor in the development of complications. A total of 159 osteotomies were included, of which 129 were HTOs. The average age was 46.16 years, and 118 patients were younger than 55 years. Seven hinge fractures were identified as the only intraoperative complication, while the overall early post-operative complication rate was 11.32%. The most frequent was deep venous thrombosis (DVT) in 5.66% of cases, followed by deep infection with a total rate of 2.52%. When performing the subgroup analysis by age, we observed a significantly higher rate of DVT in the group aged 55 years and older (p 0.036) (odds ratio 3.96 95% confidence interval 1.009-15.533; p 0.048); however, no significant differences were observed in the overall complication rate according to the age group of the patients. This study reveals that in patients undergoing osteotomies around the knee, the most common post-operative complication was DVT. The rate of DVT was significantly higher in patients aged 55 years and older, although no differences were observed in the overall complication rate according to the patients' age range. Level III (retrospective cohort study).

Chronic Deltoid Insufficiency in Stage IV Adult Acquired Flatfoot Deformity: Do We Have a Good Answer?

Stage IV adult acquired flatfoot deformity (AAFD) with secondary chronic deltoid ligament insufficiency is a challenging deformity to treat, with minimal consensus in the literature concerning its surgical management. Many surgical treatment options have been described, including joint-sparing techniques, fusions, osteotomies, and even arthroplasties. However, questions remain as to what, if any, treatment is optimal. This contribution reviews studies on surgical treatments for stage IV AAFD with deltoid ligament failure and provides a critical analysis regarding the quality of outcomes reported for those different treatment options. PubMed and Google Scholar databases were searched between June 1, 2022, and August15, 2022, for studies published between 1990 and 2022 that describe the treatment of stage IV AAFD with deltoid ligament insufficiency. Articles included in the study focused on subjects with stage IV AAFD and associated deltoid ligament insufficiency undergoing surgical correction. Exclusion criteria included stage I, II, and III AAFD, as well as deltoid ligament repair following acute injury/rupture. Nine studies covering five different treatment options for patients with stage IV AAFD and chronic deltoid insufficiency were included, with minimal overlap in outcome measures used to assess the efficacy of the procedure. Triple arthrodesis with deltoid ligament reconstruction resulted in a 62.5% (5/8) success rate with a residual tibiotalar (TT) angulation of 2°(success defined as <3°). Tibiotalar arthrodesis of four patients resulted in an average post-operative tibiotalar angulation of 4.8°with all patients showing progressive destabilization of the hindfoot complex at 12-18 year follow-ups. Deltoid arthroscopic laminoplasty (Brostrom) resulted in an increased American Orthopaedic Foot and Ankle Society (AOFAS) score from 49.7 pre-op to 91.9 post-op. There was no long-term follow-up of these patients. Deltoid ligament reconstruction using autografts of the peroneus longus resulted in a post-operative valgus of 2.1°in one study and <5°in another. Deltoid ligament reconstruction using an anterior tibial tendon autograft resulted in a gain of 126.4 + 40.2% in stiffness compared to an intact ligament. Twinfix suture anchors resulted in a post-operative hindfoot angle averaging 5.3°. Combined deltoid and spring ligament reconstruction resulted in a 5.1°valgus angulation. There is currently no standard of care or clinical consensus regarding surgical treatment for stage IV AAFD with deltoid insufficiency. Several studies imply that mild valgus malalignment around the tibiotalar joint can result in satisfactory outcomes. A few studies even deemed <5°of valgus tilt post-operatively successful. However, it has been described that any imbalance in tibiotalar tilt is a significant risk factor for progressive arthritis and future ligamentous failure. No treatment option was able to correct valgus tilt to an anatomical standard (i.e., to normal anatomy). These varied findings, along with the lack of consensus on post-surgical measures to assess efficacy, are worrisome and emphasize the need for better surgical options. Moreover, there is a critical need for additional research on the long-termoutcomes following stage IV AAFD and deltoid insufficiency repair, particularly, as over five million people in the United States and 10% of the geriatric population are affected by AAFD with a risk of progressing to stage IV.

The mediation effects of malalignment on the relation of sex to the risk of incidence tibiofemoral osteoarthritis

ObjectiveTo investigate to what extent the higher risk of tibiofemoral radiographic osteoarthritis (TFROA) in females vs. males can be explained by knee malalignment. DesignUsing data from Multicenter Osteoarthritis Study (MOST) and Osteoarthritis Initiative (OAI), we examined the relation of sex to the incident medial and lateral TFROA and performed mediation analyses to assess to what extent varus and valgus malalignments account for sex differences in the incident medial or lateral TFROA. ResultsOf the 3,462 knees without medial and lateral TFROA in MOST, the 7-year risks of medial and lateral TFROA were 16.9% and 10.0% in females, and 15.8% and 4.2% in males, respectively. Females had 2.31-fold (95% CI: 1.73 to 3.08) higher incident lateral TFROA than males, and the relative risk (RR) of the indirect effect of sex on lateral TFROA through valgus malalignment was 1.15 (95% CI:1.09 to 1.20), accounting for 23% of its total effect on lateral TFROA. In OAI (n=3,095 knees), females had 1.54-fold (95% CI:1.15 to 2.04) higher incident lateral TFROA than males, and RR of the indirect effect of sex on lateral TFROA through valgus malalignment was 1.10 (95% CI:1.04 to 1.21), accounting for 26% of its total effect on lateral TFROA. No apparent sex difference in the incident medial TFROA was found in MOST (RR=1.05, 95% CI: 0.89 to 1.25) or OAI (RR=1.02, 95% CI: 0.84 to 1.19). ConclusionFemales had a higher risk of developing lateral TFROA than males; however, valgus malalignment only modestly explained such a difference.

Surgical Technique and Preliminary Outcomes of Double-Level Osteotomy for Valgus Deformity.

Data are limited regarding the surgical technique or outcomes of double-level osteotomy (DLO) combining medial closing-wedge distal femoral osteotomy and medial closing-wedge high tibial osteotomy in patients with moderate-to-severe valgus deformity. To describe the surgical technique and assess the short-term outcomes and surgical accuracy of DLO in patients with a moderate or severe valgus deformity. It was hypothesized that this technique would result in good clinical outcomes with precise deformity correction. Case series; Level of evidence, 4. Eight patients (mean age, 44.2 ± 10.9 years) with a moderate or severe valgus knee treated with DLO (9 knees; mechanical tibiofemoral angle [mTFA], 10.3°± 3.5°) were included. The mean follow-up was 25.1 ± 11.1 months. Preoperative to postoperative changes in radiographic parameters (mTFA, mechanical lateral distal femoral angle, mechanical medial proximal tibial angle, joint line convergence angle) and clinical scores (Hospital for Special Surgery score, Oxford Knee Score, Lysholm score) were assessed. Surgical accuracy was calculated by subtracting the achieved postoperative correction from the preoperatively planned targeted correction. The mTFA changed significantly from 10.3°± 3.5° preoperatively to -1.8°± 3.4° postoperatively (P < .001); the mechanical lateral distal femoral angle and mechanical medial proximal tibial angle changed significantly by 5.1°± 2.7° and 5.9°± 2.2°, respectively (P < .001 for both); and the posterior distal femoral angle decreased significantly from 85.9°± 3.1° to 84.2°± 2.4° (P < .01). There was no significant difference between pre- and postoperative joint line convergence angles (3.3°± 2.3° to 2.6°± 2.1°). The accuracy of the correction was high: the mTFA achieved postoperatively differed from the mTFA planned preoperatively by a mean of 2.7°± 1.9° (range, 0.6°-6.6°). Significant pre- to postoperative improvement was seen for all outcome scores (Hospital for Special Surgery, from 67 ± 11 to 93 ± 4; Oxford Knee Score, from 29 ± 7 to 43 ± 3; Lysholm, from 41 ± 24 to 89 ± 8; P < .001 for all). High surgical accuracy was achieved, and patients who underwent varus DLO for valgus knees showed improved knee function at short-term follow-up. Varus DLO can be a surgical option to restore the optimal alignment and joint line obliquity in patients with moderate or severe valgus malalignment.

The effect of coronal plane angulation on patient reported outcome measures of operatively treated distal femur fractures: A multi-center prospective evaluation

ObjectivesThe goal of this trial was to determine whether coronal plane angulation affects functional and clinical outcomes after the fixation of distal femur fractures. DesignMulticenter, randomized controlled trial Setting20 academic trauma centers Patients/Participants156 patients with distal femur fractures were enrolled. 123 patients were followed 12 months. There was clinical outcome data available for 105 patients at 3 months, 95 patients at 6 months and 81 patients at one year. InterventionLateral locked plating or retrograde intramedullary nailing Main outcome measurementsRadiographic alignment, functional scoring including SMFA, Bother Index, and EQ-5D. Clinical scoring of walking ability, need for ambulatory support and ability to manage stairs. ResultsAt 3 months, there was no difference between groups (varus, neutral or valgus) with respect to any of the clinical functional outcome scores measured. At 6 months, compared to those with neutral alignment, patients with varus angulation had a worse Stair Climbing score (4.33 vs. 2.91, p = 0.05). At 12 months, the average patient with neutral or valgus alignment needed less ambulatory support than the average patient in varus. Walking distance ability was no different between the groups at any time point.With respect to the validated patient-based outcome scores, we found no statistical difference in in the SMFA, Bother, or EQ-5D between patients with valgus or varus mal-alignment and those with neutral alignment at any time point (p > 0.05). Regardless of coronal angulation, the SMFA trended towards lower (improved) scores over time, while EQ-5D scores for patients with varus angulation did not improve over time. ConclusionsValgus angulation and neutral angulation may be better tolerated in terms of clinical outcomes like stair climbing and need for ambulatory support than varus angulation, though patient reported outcome measures like the SMFA, Bother Index and EQ-5D show no statistical significance. Most patients with distal femur fractures tend to improve during the first year after injury but many remain significantly affected at 12 months post injury.

Lengthening in congenital posteromedial bowing of tibia: a follow-up series at skeletal maturity.

Congenital posteromedial bowing (CPMB) of tibia is a rare, usually self-resolving condition that is present at birth. The data on the long-term outcome of lengthening, choice of fixator, outcome in early and late age groups, and complications is sparse, hence the need for this study. This retrospective study included 93 patients with 94 affected legs from 1991 to 2023. The patients were categorized into early (under 10years) and late (10years or above) intervention groups. Eighteen patients with nineteen lengthening episodes who attained skeletal maturity made the basis of this study and will be discussed in detail. The outcome for the lengthening group at maturity was satisfactory, with 5.53cm of average length gained per lengthening episode, a mean LLD of 0.31cm at final follow-up, a mean age of 23.63years (range 14-38years), and an average follow-up of 12.51years (range 3-28years) post-lengthening, but the procedure was associated with difficulties like ankle stiffness, tibial valgus, pin tract infections, and fractures through regenerate. This study represents a large single-centre series on CPMB. We recommend that surgery for lengthening should be done at an older age, close to skeletal maturity, wherever possible to reduce the risk of repeat lengthening procedures. Based on our experience, we recommend the use of a circular fixator. Uniplanar distractors should have an adequate number and spread of Schanz screws in each segment to reduce the risk of valgus malalignment of distracting segments of bone.

Fusion Rates in Tibiotalocalcaneal Arthrodesis with Tantalum Coated Metal Cup Augmentation

Introduction/Purpose: Tantalum coated metal spacers (TCMS) have recently been utilized to fill and provide structure to large bony defects in the hindfoot. Tantalum is an appealing material due to its biocompatibility, lack of immune response generation, and structural integrity. Compared to custom printed spacers and bulk allografts, TCMS are readily available off-the-shelf implants with significantly less cost. There is currently a paucity of literature assessing the use and outcomes of TCMS in foot and ankle surgery, specifically in tibiotalocalcaneal (TTC) arthrodesis. This study serves to assess clinical outcomes and fusion rates of patients who underwent TTC arthrodesis utilizing intramedullary nailing with TCMS augmentation for large bony defects. Methods: We retrospectively identified all patients &gt; 18 years of age who underwent TTC arthrodesis with TCMS augmentation at our tertiary care center between 2015-2021. We also identified all patients who underwent TTC arthrodesis without augmentation within that time frame. The computed tomography (CT) scans at the six-month postoperative point were reviewed by one board-certified orthopaedic foot and ankle surgeon to determine fusion status, which was defined as having at least 50% fusion mass. Patient-reported outcomes measures (PROMs) including the modified foot function index (FFI) and PROMIS Global Mental Health Score were collected for patients in both groups. Patient demographics, clinical outcomes, and PROMs were compared between groups. A multivariate logistic regression model measured the effect of TCMS augmentation on the likelihood of achieving fusion. Results: Of the 65 patients included, 21 patients (32.3%) underwent TTC with TCMS augmentation. There were no significant differences in demographics between the two groups. Patients in the TCMS group had significantly higher modified FFI (91.1 + 47.6 vs 26.3 + 48.8, p&lt; 0.001) and PROMIS Global Mental Health (12.2 + 4.82 vs. 5.59 + 6.76, p&lt; 0.001) scores in the postoperative period. Overall, the fusion rate was higher for the TCMS group, however the difference was not significant between groups (90.5% vs. 80.5%, p=0.472). Multivariate logistic regression identified that TCMS augmentation was a nonsignificant predictor of increased odds of fusion at the six-month postoperative point (OR=2.87, p=0.232). Conclusion: This study is the largest to date to present 6-month postoperative CT scans demonstrating successful TTC fusion with TCMS augmentation, contributing to our understanding of its utility. Given the severity of disease and bone loss in the TCMS group, it is not surprising that post-operative patient reported outcome scores differed significantly compared to the control group. TCMS augmentation can be utilized as cost effective spacers to fill large defects in TTC arthrodesis with successful union rates. Further studies are needed to evaluate the efficacy of TCMS augmented fusions as a viable substitute to custom printed cages. Figure 1: Weight-bearing anteroposterior and lateral ankle radiographs of a patient with post-traumatic ankle arthritis and previously treated chronic osteomyelitis with valgus malalignment (A). Anteroposterior and lateral ankle radiographs status post TCMS augmented TTC arthrodesis (B). Coronal and sagittal CT scans demonstrating bony union through the TCMS augment (C).

Valgus malalignment causes increased forces on a medial collateral ligament reconstruction under dynamic valgus loading: Abiomechanical study.

To investigate the forces on a medial collateral ligament (MCL) reconstruction (MCLR) relative to the valgus alignment of the knee. Eight fresh-frozen human cadaveric knees were subjected to dynamic valgus loading at 400 N using a custom-made kinematics rig. After resection of the superficial medial collateral ligament, a single-bundle MCLR with a hamstring tendon autograft was performed. A medial opening wedge distal femoral osteotomy was performed and fixed with an external fixator to gradually adjust the alignment in 5°increments from 0° to 10° valgus. For each degree of valgus deformity, the resulting forces acting on the MCLR were measured through a force sensor and captured in 15° increments from 0° to 60° of knee flexion. Irrespective of the degree of knee flexion, increasing valgus malalignment resulted in significantly increased forces acting on the MCLR compared to neutral alignment (p < 0.05). Dynamic loading at 5° valgus resulted in increased forces on the MCLR at all flexion angles ranging between 16.2 Nand 18.5 N (p < 0.05 from 0° to 30°; p < 0.01 from 45° to 60°). A 10° valgus malalignment further increased the forces on the MCLR at all flexion angles ranging between 29.4 Nand 40.0 N (p < 0.01 from 0° to 45°, p < 0.05 at 60°). Valgus malalignment of the knee caused increased forces acting on the reconstructed MCL. In cases of chronic medial instabilities accompanied by a valgus deformity ≥ 5°, a realigning osteotomy should be considered concomitantly to the MCLR to protect the graft and potentially reduce graft failures. Level III.

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

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. 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. 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. 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.

Normal and malaligned talonavicular fusion alters cadaveric foot pressure and kinematics.

Talonavicular (TN) fusion is a common treatment for TN arthritis or deformity correction. There is incongruous evidence regarding remaining motion at the talocalcaneal and calcaneocuboid joints after TN fusion. Additionally, the effects of a malaligned TN fusion are not well understood and alignment of the fusion may be important for overall foot integrity. This project assessed the kinematic and kinetic effects of neutral and malaligned TN fusions. Ten cadaveric feet were tested on a gait simulator in four conditions: unfused, fused in neutral, fused in varus, and fused in valgus. The fusions were simulated with external fixation hardware. An eight-camera motion analysis system and a 10-segment foot model generated kinematic data, and a pressure mat captured pressure data. Simulated TN fusion was achieved in eight feet. From unfused to fused-neutral, range of motion (ROM) was not eliminated in the adjacent joints, but the positions of the joints changed significantly throughout stance phase. Furthermore, the ROM increased at the tibiotalar joint. Plantar pressure and center of pressure shifted laterally with neutral fusion. The malalignments marginally affected the ROM but changed joint positions throughout stance phase. Pressure patterns were shifted laterally in varus malalignment and medially in valgus malalignment. The residual motion and the altered kinematics at the joints in the triple joint complex after TN fusion may subsequently increase the incidence of arthritis. Clinical significance: This study quantifies the effects of talonavicular fusion and malalignment on the other joints of the triple joint complex.

Varus osteotomy as a salvage procedure for young patients with symptomatic patellofemoral arthritis and valgus malalignment at short- to mid-term follow-up: a case series

PurposeThe purpose of the study was to report the clinical, functional and radiological outcome following varus osteotomy as a salvage procedure in young to middle-aged patients with patellofemoral arthritis (PFA) and associated valgus malalignment. It was hypothesized that a significant improvement in knee function and reduction in pain would be achieved. Moreover, no conversion to patellofemoral joint arthroplasty could be observed.Material and methodsPatients (< 50 years of age) that underwent varus osteotomy between 08/2012 and 01/2020 for the treatment of symptomatic PFA and associated valgus malalignment were consecutively included (minimum follow-up: 24 months). Patient-reported outcome measures (PROM; International Knee Documentation Committee subjective knee form [IKDC]), Visual Analog Scale [VAS] for pain, Tegner Activity Scale [TAS], and satisfaction with the postoperative results (1–10-scale, 10 = highest satisfaction) and weight-bearing whole-leg anteroposterior radiographs were conducted pre- and postoperatively. The change in PROM and femorotibial angle (FTA) were tested for statistical significance.ResultsIn total, 12 patients (14 knees) were included (66.7% female; mean age: 33.8 ± SD 6.6 years). In ten cases, lateral opening-wedge distal femoral osteotomies (DFO) were performed, of which three cases included a concomitant femoral derotation. Three medial closing-wedge DFO and one medial closing-wedge high tibial osteotomy were performed. At follow-up (55.3 ± 29.3 months), a significant improvement in knee function (IKDC: 56.4 ± 14.4 to 69.1 ± 11.2, p = 0.015) and reduction in pain (VAS for pain: 3.5 [interquartile range 2.3–5.8] to 0.5 [0–2.0], p = 0.018) were observed. Patients were able to reach their preoperative sporting activity level (TAS: 3.0 [3.0–4.0] to 3.5 [3.0–4.0], p = 0.854) and were highly satisfied with the postoperative result (9.0 [6.5–10]). Additionally, a significant correction of valgus malalignment was observed (5.0° ± 2.9° valgus to 0.7° ± 3.2° varus, p < 0.001). Regarding complications, two re-osteosyntheses were performed due to loss of correction and delayed union. No conversion to patellofemoral arthroplasty occurred.ConclusionIn patients with symptomatic PFA and associated valgus malalignment, varus osteotomy as a salvage procedure achieved a significant improvement in knee function and reduction in pain. No conversion to patellofemoral joint arthroplasty occurred at short- to mid-term follow-up.Level of evidenceRetrospective case series, Level IV.

Tibial tuberosity-trochlear groove distance is significantly decreased by medial closing wedge distal femoral osteotomy.

While medial closing wedge distal femoral osteotomy (MCWDFO) has been used to address patella instability combined with valgus malalignment, its impact on patellofemoral parameters remains uncharted. Hence, this study seeks to establish a three-dimensional (3D) planning of MCWDFO and measure its effect on the tibial tubercle - trochlear groove distance (TTTG) through simulation and calculation. MCWDFO with a stepwise increment of one-degree varisation (1°-15°) was performed on 3D surface models of 14 lower extremities with valgus malalignment and 24 lower extremities with neutral alignment of the lower limb, resulting in a total of 608 simulations. Anatomic landmarks were employed to measure hip-knee-ankle angle (HKA), TTTG, and femoral torsion for each simulation. A mathematical formula was adopted to calculate TTTG changes following MCWDFO, and subsequently the mean simulated and calculated TTTG values were compared. Following a standardised protocol, MCWDFO was performed without rotational changes. MCWDFO exhibited an almost linear reduction in TTTG, at a rate of approximately -1.05 ± 0.13 mm per 1° of varisation, demonstrating a strong negative correlation (R = -0.83; p < 0.001). Limb alignment did not exert an influence on TTTG change; however, it correlated with tibial plateau width. The mean difference between the simulated and calculated TTTG values amounted to 0.03 ± 0.03 mm per 1° varisation (p < 0.001). The TTTG distance is linearly reduced by 1.05 mm for every 1° of varisation within the varus correction range of 0°-15° during MCWDFO. Patients with combined valgus and patellar instability may benefit from MCWDFO due to frequently pathological TTTG. Level III, descriptive laboratory study.