Osteotomy Fixation Research Articles

The surgical strategy selection and clinical efficacy analysis of Kummell's disease.

To evaluate the clinical efficacy of surgery in Kummell's disease (KD) to help us select the optimum surgical strategy. We included 67 KD patients who underwent Percutaneous vertebral plasty (PVP), Percutaneous kyphosis plasty (PKP), Percutaneous pedicle screw fixation (PPSF) or Posterior decompression osteotomy fixation (PDOF). The differences in imaging parameters and prognosis changes of pre-operation, post-operative and follow-up endpoint were analyzed. The incidence rate of KD was 10.02% (67/668) in vertebral compressibility fracture. 80.60% of patients underwent PVP/PKP, 14.93% underwent PPSF, and 4.47% underwent PDOF. The significant differences between the actual used surgical methods and the classification recommended surgical strategies could be found. In I type, there was no significant difference in total improvement of the radiography data and clinical efficacy between PVP and PKP. In II type, there was a significant correlation between opening and closing sign (OCS) and surgical choice. Compared with PPSF, the positive OCS patients who underwent PVP/PKP suffered a poor prognosis. PDOF is an effective surgical method for type III, but PVP could also achieve a good prognosis for patients with poor condition. The mainstream KD classification system has shortcomings, and completely following its treatment strategy may lead to poor prognosis. Compared to PKP, PVP is a better choice for type I patients. OCS is one of the important factors in surgical selection for type II patients. The Li's type III is mainly treated with PDOF but the overall condition of the body needs to be evaluated.

Finite element analysis of distraction osteogenesis with a new extramedullary internal distractor

Distraction osteogenesis (DO) is a bone regenerative maneuver, which is conventionally done with external fixators and, more recently, with telescopic intramedullary nails. Despite the proven effectiveness, external approaches are intrusive to the patient’s life while intramedullary nailing damages the growth plates, making them unsuitable for pediatric patients. An internal DO plate fixator (IDOPF) was developed for pediatric patients to address these limitations. The objective of this study was to test the hypothesis that the IDOPF can withstand a partial weight bearing scenario and create a favorable mechanical microenvironment at the osteotomy gap for bone regeneration as the device elongates. A finite element model of a surrogated long bone diaphysis osteotomy fixation by means of the IDOPF was created and subjected to axial compression, bending and torsion. As the osteotomy gap increased from 2 mm to 20 mm, under compression, The average axial interfragmentary strains decreased from 2.33% to 0.35%. Stress increased from 179 MPa to 281 MPa at the contact interfaces of the telescopic compartments, which exceeded the endurance limit of stainless steel (270 MPa) but was below its yield limit (415 MPa). These results demonstrate, that the IDOPF can withstand a partial load bearing scenario and provide a stable biomechanical environment conductive to bone healing. However, high contact stresses at the telescopic interfaces of the device are likely to cause wear, as is frequently reported in telescopic fixators. This study is a step towards refining the IDOPF design for clinical use.

Pin fixation is an effective method for fixation of bunion osteotomy with various procedures: a retrospective cohort study

BackgroundVarious fixation devices are available for bunion osteotomy. In this study, we evaluated the radiographic outcomes, postoperative complications, and recurrence rate in a series of hallux valgus deformities treated with various osteotomy procedures using a pin for the fixation of the osteotomy.MethodsTwo-hundred forty-seven patients with hallux valgus deformity managed with a Simple, Effective, Rapid and Inexpensive (SERI) osteotomy, distal chevron osteotomy, or proximal crescentic osteotomy and K-wire fixation were included. The mean follow-up of the patients was 53.9 ± 8.9 months. Radiographic evaluations included the assessment of the Hallux valgus angle (HVA), intermetatarsal angle (IMA), and union. Clinical evaluations included the assessment of the range of motion, pain in the first metatarsophalangeal joint, and patient satisfaction.ResultsIn the last visit, the mean improvement of HVA was 23.9 ± 9.1º (P < 0.001). The mean IMA improvement was 6.1 ± 6º (P < 0.001). The mean metatarsophalangeal flexion and extension were 33 ± 10.7º and 34.6 ± 9.2º, respectively. Postoperative complications included pin tract infection in eight (3.2%) patients, deep infection in five (2%) patients, and early pin complication in four (1.6%) patients. Recurrence was observed in five (2%) patients. Twenty-three (9.3%) patients had slight pain in the last follow-up. The mean surgical time was smaller in the SERI osteotomy (P < 0.001). The mean hospitalization period was longer in the proximal osteotomy group (P = 0.039). The mean metatarsophalangeal flexion and extension were significantly smaller in the distal chevron osteotomy (P = 0.046 and P = 0.037, respectively). 90% of patients were satisfied or very satisfied with the surgical outcomes.ConclusionK-wire fixation is a safe and effective device for the fixation of bunion osteotomy, and this effectiveness is even higher with SERI and proximal crescentic osteotomy.

Oblique Dorsiflexion Osteotomy of the Distal Tibia for Fixed Ankle Equinus: Surgical Technique.

There are significant challenges in the treatment of a severe rigid ankle equinus caused by a flat-topped talus, arthrogryposis, burn sequelae, or extensive scarring. Conventional approaches, such as soft tissue releases, often fail due to joint incongruence or compromised soft tissues, thereby necessitating supramalleolar osteotomies. The classic transverse supramalleolar osteotomy (TSO) of the distal tibia can lead to secondary anterior translation of the centre of rotation of the ankle and alters mechanical and anatomical axes. An alternative technique involves an oblique closing wedge osteotomy of the distal tibia, with a fulcrum near the ankle joint. This technical note delineates the planning parameters and procedural steps for the oblique dorsiflexion osteotomy of the distal tibia (ODODT). Using an anterior approach to the distal tibia, the "alpha angle," which determines the size of the closing wedge required for the foot to be plantigrade, is resected with a fulcrum at the most posterior part of the ankle joint, ensuring that the posterior cortex remains intact. The inclination of this resected wedge is planned preoperatively and is referred to as the "beta angle." This aims to equalise the lengths on both sides of the osteotomy. For osteotomy fixation, 2 or 3 cannulated screws in lag mode are employed. Postoperatively, a short cast boot is used for 6 weeks. The ODODT is a salvage solution for severe rigid ankle equinus when first-line foot and ankle procedures are impractical due to tibiotalar incongruence or poor soft tissues. Advantages include minimal translation of the centre of rotation of the ankle, excellent stability when the posterior cortex remains intact, avoidance of large internal fixation devices, and cost-effectiveness, making it suitable for low-resource settings. Olleac R, Farfan F, Acosta L, et al. Oblique Dorsiflexion Osteotomy of the Distal Tibia for Fixed Ankle Equinus: Surgical Technique. Strategies Trauma Limb Reconstr 2024;19(2):104-110.

Is headless screw a valid alternative for the fixation of Chevron olecranon osteotomy? A biomechanical comparison of 4 fixation methods

BackgroundChevron osteotomy is a popular technique for repairing complex distal humerus intraarticular fractures. However, re-fixation presents challenges like hardware prominence and soft tissue damage. Headless cannulated screws are gaining popularity for fixation due to better bone purchase and less irritation. This study aims to compare different fixation strategies with headless screws for chevron osteotomy fixation. MethodsThis study utilized 32 polyurethane foam ulna specimens for biomechanical testing. The Chevron osteotomy was performed with an oscillating saw for all specimens. Four different techniques were used for re-fixation: modified tension band wire fixation, plate-screw fixation, cannulated screw fixation, and headless cannulated screw fixation. The constructs were mounted to the testing machine, simulating the elbow in 90 degrees of flexion. All specimens were tested under axial traction. Displacements at 350N and 500N and loads at the failure were recorded. ResultsAt the load of the implant failure, headless cannulated screw fixation revealed higher force values when compared to the other constructs, and modified tension band wire fixation showed lower force values compared to the other three groups (p < 0.001). The headless cannulated screw fixation group showed no significant differences in osteotomy displacements when tested to a 350N load. There were no significant differences in displacements at a 500N load between the four groups (p = 0.275). ConclusionThis study suggests that headless cannulated screw fixation is a viable and effective option for Chevron osteotomies. Headless cannulated screw fixation makes it a promising alternative to traditional fixation methods. This technique may be a more reliable fixation technique during daily activities and moderate elbow motions, indicating that it has the potential to succeed.

Clinical outcomes for linked fixation of distal humerus fractures: a multicenter study

BackgroundO’Driscoll popularized the principle of linked column fixation for distal humerus fractures. Despite the linked column concept being widely accepted, there are few reported techniques to accomplish this goal. A novel device was designed based on the principles of linked columns. An interlocking beam is used to connect the medial and lateral plates, creating a unified fixed angle construct. Our primary objective was to report clinical outcomes across multiple institutions for a linking beam used in distal humerus fracture fixation. MethodsA retrospective series was collected from five institutions for the TiBeam (Skeletal Dynamics, Miami, FL, USA) with a minimum follow-up of six months. Acute and chronic treatment of distal humerus fracture patterns, and all plate configurations were included for analysis. ResultsA total of 36 cases were collected at a mean age of 52 years and a mean follow-up of 19.3 months. AO C-type fractures were 56% of the series. The median MEPS was 85 (IQR 76.3 to 90), the median DASH was 21.4 (IQR 15.9 to 30), and the median VASa was 3.5 (IQR 2 to 5). An olecranon osteotomy was used in 86% of cases and an anatomic plate was used for fixation of the osteotomy in 94% of those cases. There were three cases of olecranon plate removal for a rate across the series of 13.7%. DiscussionOur short-term results demonstrate satisfactory clinical outcomes with low rates of revision for distal humerus fracture fixed with a linking beam. Further, the rate of removal for the olecranon osteotomy plate was lower than historical reports for aggregate methods of osteotomy fixation.

Superior accuracy in knee double level osteotomy using a novel hybrid fixation technique compared to conventional double plating.

This study aimed to compare two different double-level knee osteotomy (DLO) fixation techniques. The primary outcome reported the radiological coronal plane correction and its accuracy. The secondary outcomes reported the correction outliers, the clinical outcomes, the 5-year postoperative satisfaction and the complications. A retrospective review of a single surgeon osteotomy database identified 52 cases of DLO between 2011 and 2019, of which 24 cases met the inclusion criteria. Patients were categorised into two groups: the nail-plate (NP) group fixed with a magnetic extendable intramedullary tibial nail and femoral conventional plate, and the double-plate (DP) group fixed with conventional plates (tibia and femur). Radiographic parameters were recorded, including the mechanical femorotibial angle (mFTA), medial proximal tibial angle (MPTA), mechanical lateral distal femoral angle (mLDFA), joint line convergence angle (JLCA) and weight-bearing line ratio (Mikulicz %). Surgical accuracy was calculated as the difference between the achieved and the planned correction. Outliers were defined as those with a greater than 10% difference from the planned correction. Simple knee value scores and visual analogue scale for pain were recorded preoperatively and postoperatively at 2 and 5 years. Five-year patient satisfaction was recorded. A total of 24 patients were included: the NP group (n = 12) and the DP group (n = 12). Significant coronal plane corrections were achieved in the NP group for the mean mFTA (preoperative 167.9° ± 3.4° to postoperative 182.1° ± 1.4°), the mean MPTA (preoperative 83.5° ± 2.9° to postoperative 91.3° ± 2.8°) and the mean mLDFA (preoperative 89.8° ± 3.4° to postoperative 85.9° ± 4.4°). Similarly, significant coronal plane corrections were achieved in the DP group for the mean mFTA (preoperative 168.6° ± 4.4° to postoperative 182.2° ± 2°), the mean MPTA (preoperative 84.2° ± 2° to postoperative 88.3° ± 4.1°) and the mean mLDFA (preoperative 90.7° ± 2.9° to postoperative 83.9° ± 1.7°) (all p < 0.05). The mean correction accuracy was higher for the NP versus DP group at 3.4 ± 3.4% versus 7.1 ± 3.9% (intergroup p < 0.05). There were no outliers in the NP group versus two outliers (overcorrected) (16.7%) in the DP group. Significant clinical improvement was reported in both groups at 2 and 5 years postoperatively (all p < 0.05). Superior correction accuracy and no outliers were achieved in hybrid fixation double-level knee osteotomy compared to the conventional double-plating technique. The magnetic extendable nail offers the advantage of fine-tuning the correction postoperatively and could be a potential research template for future designs of postoperative correction implants. Level III, retrospective cohort study.

Effect of Plate Configuration in the Primary Stability of Osteotomies and Biological Reconstructions of Femoral Defects: Finite-Element Study.

Osteosynthesis is an alternative treatment for stabilizing femur-bone traumas. The initial stability of the fixation systems is one of the biomechanical parameters affecting implant failure and bone union, especially in surgeries of intercalary reconstructions after the removal of bone tumors. This study aimed to investigate the initial biomechanical effect of using one or two osteosynthesis plate configurations for femoral fixation and the effect of fastening the allograft to the osteosynthesis plate in the case of femoral allograft reconstructions. Three finite-element models of a femur with three different fixation conditions for a transverse osteotomy in the middle of the diaphysis, i.e., using one and two osteosynthesis plates and an intercalary allograft, were constructed. An eight-hole compression plate and a six-hole second plate were used to simulate osteosynthesis plates. The plate screws were tightened previously to the loading, and the tightening sequences simulate the bolt-tightening procedure in a surgical environment. The models were imported into the ADINA System for nonlinear analysis, using compression loads applied over the femur head. Models with the dual fixation systems had the most outstanding compression stiffness. The femur head movement in the dual plate system was 24.8% smaller than in the single plate system. A statistical analysis of a region of interest (VOI) placed in the femur diaphysis showed that the biomechanical effect of using the dual plate system is smaller in the osteotomy region than at the femur head, e.g., a displacement average decrease of only 5% between the two systems, while the maximum value decreases by 26.8%. The allograft fixation to the second osteosynthesis plate leads to an improvement in the system stability. The results presented in this work show that including the bolt analysis in the femoral diaphysis osteotomy fixation will allow for capturing the nonlinear behavior of the osteotomy region more realistically. The stability of the intercalary reconstruction of the femoral diaphysis was higher when the allograft was fastened to the second osteosynthesis plate.

Comparison of two versus three-screw fixation for biplanar chevron medial malleolar osteotomy.

This study was designed to compare the clinical outcomes and complications of using two versus three screws to fix the biplanar chevron medial malleolar osteotomy (MMO). A retrospective review was conducted on 43 patients (46 ankles) who underwent biplanar chevron MMO to treat talus osteochondral lesions. Of these, MMO was fixed with two parallel screws placed perpendicular to the osteotomy plane in 16 ankles, while in the remaining 30 ankles, MMO was secured with two parallel screws plus an additional third screw inserted parallel to the tibial plafond. Patients were divided into two groups based on the fixation method and clinical outcomes, union and malunion rates, and complications were compared. Demographic and clinical characteristics such as age (p: 0.411), gender distribution (p: 0.119), affected side (p: 0.126), lesion grades (p: 0.056), and lesion sizes (p: 0.310), immobilization (p: 0.119) and weight-bearing periods (p: 0.252) were statistically similar across both groups. Initial malreduction were observed in five cases within the three-screw group and one case in the two-screw group (p: 0.307). However, neither group exhibited any progressive step-off or gap in the follow-up radiographs, and osteotomy union was achieved in all patients. Delayed union was observed in one patient from the three-screw group. Significant improvements in American Orthopedic Foot and Ankle Society scores were observed in both groups, with no functional discrepancies evident at the final follow-up (p: 0.488). The study found no significant differences in union rates, complications, or clinical outcomes between two and three-screw fixation methods for medial malleolar osteotomies (MMO). Both methods allowed for effective MMO fixation without loss or displacement post-surgery, suggesting their safety and efficacy. Level III, retrospective comparison.

Minimally invasive Chevron-Akin (MICA) osteotomies without Akin fixation in hallux valgus correction: a case series with 2-year follow-up.

The minimally invasive Chevron-Akin (MICA) is considered the third generation of minimally invasive hallux valgus (HV) surgery, and its original description included fixation of the Akin osteotomy with a screw. The aim of this study is to evaluate a series of patients undergoing HV correction using the MICA technique without screw fixation of the Akin osteotomy. We retrospectively evaluated 58 consecutive patients who underwent surgical correction for HV between August 2018 and March 2020. A total of 69 feet were evaluated with a minimum follow-up of 2years. Clinical outcomes such as pain (VAS), function (AOFAS), range of movement, criteria personal satisfaction and complications were evaluated. The AOFAS score (mean ± standard deviation) significantly improved from 57.0 ± 8.6 preoperatively to 93.9 ± 8.7 postoperatively (p < .001) with a minimum follow-up of 2years. The VAS score improved from 6.0 ± 1.8 preoperatively to 0.6 ± 1.4 at 2-year follow-up (p < .001), and the hallux valgus angle reduced from 39.7 ± 6.9 to 8.9 ± 9.0 (p < .001). The majority of patients (95.6%) reported the result as excellent or good, and the most common complication was the need to remove the screw (7.2%). The use of MICA without Akin osteotomy fixation resulted in successful correction of hallux valgus with improvements in clinical and radiographic parameters. IV, case series.

Akin Osteotomy: A Review of Modern Fixation Techniques.

Akin osteotomy is commonly used to correct hallux valgus interphalangeus (HVI) deformity. The preferred implant for fixation remains an area of debate, often influenced by the surgeon's inclinations and expertise. This review compares the outcomes of contemporary fixation methods utilized in Akin osteotomy. PubMed served as the primary electronic database for the search. The interventions encompassed the use of screw(s), staple(s), and suture(s). The participants considered were adults aged 18 and above, undergoing Akin osteotomy either as a primary procedure or as an adjunct. Excluded were osteotomies performed via percutaneous or minimally invasive methods. Seven studies involving 590 feet were analysed, showcasing an impressive 99.8% overall union rate. The incidence of overall complications stood at 8.98%, with metal prominence notably higher in the screw fixation group (10.5%). All studies exhibited postoperative improvement in radiological angles. Screw, staple, and suture fixations demonstrated excellent union rates. While screws and staples offer robust osteotomy fixation, they pose risks of metal irritation and prominence. Suture fixation delivers comparable outcomes to the other two stabilization methods at a lower cost.

Locking plate versus K-wires and cast fixation in lateral closing-wedge osteotomy for cubitus varus deformity.

The aim of this study was to assess the clinical and radiographic outcomes of cubitus varus treatments based on different fixation methods: Locking plate vs. Kirschner-wires (K-wires) and cast fixation. This retrospective study of 28 patients was performed in lateral-wedge osteotomy for cubitus varus deformity in our hospital from July 2018 to July 2020. 14 patients in group A were treated by locking plate after lateral closing-wedge osteotomy, whereas other 14 patients were treated by K-wires in group B. We measured the bony union and carrying angle. The clinical and radiographic outcomes were assessed according to the Bellemore criteria. No nonunion, neurovascular injury or myositis ossificans was noted at follow-up. In group A, 1 patient with lateral condylar prominence was found. In group B, 2 patients with pinning site infection were treated successfully with oral antibiotics and 2 patients needed revision surgery for residual varus. According to the Bellemore criteria, statistically significant difference was noted between the two groups (P = 0.0458). In the present study, no statistically significant difference was noted in the length of incision and operation time between the 2 groups (P > 0.05). However, the postoperative carrying angle was significantly different at final follow-up between the 2 groups (P < 0.01). Compared with K-wires and cast fixation, we recommend the wedge osteotomy with lateral locking plate to treat the cubitus varus deformity because locking plate could achieve better functional and cosmetic results and stabilize the distal humerus rigidly.

Effect of Carbon Fiber Reinforced Peek on Stabilization of Sagittal Split Ramus Osteotomy Fixation and Stresses on Temporomandibular Joint: 3d Finite Element Analysis Study

Effect of Carbon Fiber Reinforced Peek on Stabilization of Sagittal Split Ramus Osteotomy Fixation and Stresses on Temporomandibular Joint: 3d Finite Element Analysis Study

The Triple Varus Knee: A Case Presentation

Background: Knee instability due to posterior cruciate ligament (PCL) and posterolateral corner (PLC) deficiency is a devastating condition that negatively affects patient quality of life. This video presents the surgical management of a triple varus knee, including combined high tibial osteotomy (HTO), revision PCL and PLC reconstruction, and meniscus root repair. Indications: Combined HTO and revision PCL and PLC reconstruction is indicated for patients with previously failed PCL and PLC reconstruction in the setting of varus malalignment. Technique Description: The procedure begins with a medial opening-wedge biplanar HTO, which is fixed with a patient-specific locking plate. The PCL femoral tunnel is drilled via a low anterolateral portal, and the tibial insertion is debrided via a posteromedial portal. The medial meniscus is carefully freed from the posterior capsule, and 2 luggage tag sutures are placed through the posterior root. The PCL tibial tunnel and meniscus root tunnels are drilled via their respective guides. The meniscal sutures are passed through the tunnel but not fixed. An Achilles bone-block allograft is passed through the PCL tibial tunnel and fixed with suspensory fixation and an interference screw on the femoral side, while the tibial side is left free. A peroneal nerve neurolysis is performed. A fibular tunnel is drilled, and a semitendinosus allograft is whip-stitched on both sides and passed through the tunnel. A Beath pin is inserted into the femur, and the tunnel is over drilled. Both limbs of the graft are passed deep to the iliotibial band and into the tunnel. The tibial side of the PCL is fixed with an interference screw at 90° of knee flexion. The PLC grafts are fixed with an interference screw at 30° of knee flexion with slight valgus. The medial meniscus root sutures are tied over a button, with 60° of knee flexion. Screws from osteotomy fixation are replaced as needed. Results: Although outcomes following the combined procedure are lacking, good to excellent clinical outcomes have been reported in isolation following each procedure. Conclusion: A combination of HTO and revision PCL and PLC reconstruction should be considered for patients with persistent instability and/or pain in the setting of triple varus knee. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Biomechanical comparison of rotational stability of long and short plates in fixation of high tibial osteotomies in the surgical treatment of osteoarthritis

Biomechanical comparison of rotational stability of long and short plates in fixation of high tibial osteotomies in the surgical treatment of osteoarthritis

Trochanteric Claw Plate Fixation for Greater Trochanteric Fracture or Osteotomy in Total Hip Arthroplasty.

This study retrospectively evaluated 41 consecutive open reductions and internal fixations following primary or revision total hip arthroplasty, which required trochanteric claw plate fixation for greater trochanteric fracture or osteotomy between January 2008 and December 2020. The mean duration of clinical follow-up was 4.2 years (range, 1-13 years). The patients included 13 men and 28 women, with a mean age of 68 years (range, 32-87 years). The indications for intervention included trochanteric osteotomy, intraoperative fracture, and non-union including postoperative fracture in 6, 9, and 26 cases, respectively. The mean Merle d'Aubigné Clinical Score improved from 9.4 points (range, 5-15 points) pre-operatively, to 14.3 points (range, 9-18 points) at the last follow-up. Bone union occurred in 35 cases (85%), while implant breakage occurred in four cases. At the last follow-up, the mean Merle d'Aubigné Clinical Scores of bone union and non-union were 15.3 and 14.1, respectively (p=0.48). The Kaplan-Meier survival rate, with the endpoint being revision surgery for pain, non-union, dislocation, or implant breakage, at 10 years was 80.0% (95% confidence interval: 62.6-97.4%). Greater trochanteric fixation using a trochanteric claw plate yielded successful results.

A neck-sparing short stem shows significantly lower blood loss in total hip arthroplasty compared to a neck-resecting short stem

Short stems are associated with a significantly lower blood loss (BL) compared to straight stems in total hip arthroplasty (THA). Different types of stems differ in design, fixation and level of femoral neck osteotomy. Therefore, we sought to evaluate the difference regarding the perioperative BL between two short stems with different designs in direct anterior approach (DAA). A total of 187 THA performed by a single surgeon were analysed. 107 patients received a neck-resecting (Group A) and 80 patients a neck-sparing short stem (Group B). Blood counts of the day before surgery and of two days after surgery were evaluated. Total blood volume and BL were calculated. Additionally, duration of surgery was analysed. The perioperative BL was significantly lower in Group B (451.4 ± 188.4 ml) compared to Group A (546.6 ± 232.7 ml; p = 0.002). The postoperative haematocrit (31.6 ± 3.7% vs. 30.4 ± 4.4%; p = 0.049) and haemoglobin-level (11.0 ± 1.3 g/dL vs. 10.4 ± 1.5 g/dL; p = 0.002) were significantly higher in Group B. Duration of surgery was significantly shorter in Group B (62.0 ± 11.4 min vs. 72.6 ± 21.8 min; p < 0.001). The use of a neck-sparing short stem leads to a significantly decreased BL compared to a neck-resecting short stem in DAA THA. A less extensively conducted capsular release necessary for optimal femoral exposition might lead to a lower perioperative BL and shorter durations of surgery.

Biomechanical Evaluation of Different Fixation Methods for a First Metatarsal Transverse Neck Osteotomy in a Hallux Valgus Sawbone Model

Category: Bunion Introduction/Purpose: There are no studies available that provide information about fixation methods for minimally invasive Hallux Valgus osteotomies. Our objective was to evaluate different fixation methods' strength for a first metatarsal transverse neck osteotomy in a sawbone model. Methods: 30 sawbone foot models were used. Transverse neck first metatasal osteotomies were performed and fixed in a standardized fashion in 6 different configurations. Group 1 used one 4.0 screw; Group 2 used two (one 4.0 and one 3.0) parallel screws; Group 3 used two (one 4.0 and one 3.0) divergent screws; Group 4 used two divergent screws, one 4.0 with lateral metatarsal head cortex purchase, and one 3.0 screw; Group 5 was like Group 4, but with two 4.0 screws. Group 6 was like Group 4 and 5, but with two 3.5 screws. Cyclic and load to failure testing were performed, measuring stiffness and force needed to create deformity, using a Zwick Roell Universal Testing Machine. Results: Group 1 failed due to rotational instability. Group 2 showed increased stiffness (p &lt; 0.05) against group 1. Group 3 did not achieve difference to group 2. Group 4 was stronger (p &lt; 0.05) in all variables than groups 1-3. Group 5 did not show differences against Group 4. Group 6 was only stronger than Group 1-2. Conclusion: In this study, better biomechanical behavior is seen using divergent screws with lateral head cortex purchase. This is the first study that provides biomechanical information on first metatarsal transverse neck osteotomy fixation methods. Clinical studies are needed to evaluate the clinical impact of these findings.

Medial malleolar fixation with bioabsorbable magnesium screws; a retrospective study with a mean follow-up of 5 years

BackgroundThis retrospective study aimed to investigate the mid-term clinical and radiological results of medial malleolar fixation with bioabsorbable magnesium screws. Methods44 patients who underwent a medial malleolar fixation for either fracture or osteotomy with magnesium bioabsorbable compression screws between 2015 and 2020 were retrospectively reviewed. Medial malleolar osteotomy was used for cartilage restorative procedures of talus osteochondral lesions (TOL), and biplanar chevron osteotomy was performed in all of them. Clinical results were evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) scale during the final follow-up. Bone healing, loss of reduction, gas formation, implant failure, and resorption were examined through available serial radiographs. All complications were also documented and reported. ResultsPatients were followed with a mean of 61.3 ± 20.2 months (range 27–94). The mean AOFAS score at the final clinical follow-up was 91.6 ± 10.3 points (range 52–100). The postoperative AOFAS score significantly improved in TOL cases compared to preoperative scores (p: 0.001, 46.4 ± 15.0, and 89.1 ± 11.2, respectively). The final radiographic examination showed no signs of ankle osteoarthritis in 36 patients (Grade 0) and Grade I ankle osteoarthritis in eight. Only one patient had a nonunion and was revised with titanium screws. Another patient had early screw breakage but recovered without intervention. ConclusionsThis is the first study that reports the mid-term results of Mg bioabsorbable screws in the current literature. The findings in the present study indicate that Mg bioabsorbable screw fixation might be a good alternative for medial malleolar fracture or osteotomy fixation with a high rate of union and low rate of complications. Besides, it eliminates the need for implant removal.Level of evidence: Level IV, therapeutic, retrospective case series.

Use of Locking Plates Fixed with Cortical Screws for Pelvic Fracture Repair in 20 Cats.

The aim of this study is to describe the use of String of Pearls (SOP) plates for the surgical management of feline pelvic fractures, including surgical technique, proposed indications, complications, and outcomes in a cohort of cats. This study is a single-center retrospective clinical case series. Medical records (2015-2019) of cats presenting for pelvic fractures (n = 33) were reviewed. Type of fracture, preoperative and postoperative imaging, and complications were retrospectively retrieved. Owners were contacted via questionnaire for medium- and long-term follow-up. A total of 20 cats met the inclusion criteria. Minor intraoperative complications were encountered in three patients. One patient suffered a major intraoperative complication. Five major complications were encountered postoperatively. These included two greater trochanter osteotomy fixation implant removal and three SOP plate removal. Full function was recovered in all patients according to the owners' assessment. The use of SOP plates in feline pelvic fractures appears to yield a consistently good outcome with a very low incidence of canal narrowing and screw loosening. SOP plates are easy to contour and to apply along the entire pelvic length.