Parallel versus Angulated Screw Configuration in Subtalar Arthrodesis for Posttraumatic Arthritis.

Background: To compare radiographic union and clinical outcomes between parallel and angulated screw configurations (SCs) for patients undergoing subtalar arthrodesis due to posttraumatic subtalar arthritis (PSA) after displaced intra-articular calcaneal fractures. Methods: This study retrospectively reviewed 140 consecutive PSA cases from March 2011 to November 2021 (parallel SC: group 1, n = 80; angulated SC: group 2, n = 60). Radiographic union, Foot and Ankle Outcome Score (FAOS), and visual analog scale (VAS) scores were among the outcome assessments. Six months after surgery, nonunion was confirmed based on plain radiographs, clinical evaluation, and computed tomography. Results: Groups 1 and 2 included 14 (17.5%) and 3 (5.0%) nonunion cases, respectively (p = 0.035). There was no significant difference in preoperative FAOS and VAS scores between the groups. However, group 2 had significantly better clinical outcomes in 2 of the 5 FAOS domains (sports and quality of life), as well as VAS scores at 3 and 6 months postoperatively and at the final follow-up (p < 0.05). Conclusions: Using the angulated SC for PSA had a lower nonunion rate and superior clinical outcomes than the parallel SC. Obtaining better radiological and clinical outcomes when using the angulated SC, rather than the parallel SC, would be advantageous.

Intra-articular Calcaneal Fractures: A Report of Cases and Comments on Preoperative Management.

OBJECTIVES: To present a review of the clinical characteristics, preoperative and surgical management, and outcomes of patients with intra-articular calcaneal fractures who had open reduction and internal fixation (ORIF) and to offer some comments on and research ideas for the preoperative management of patients with these fractures. PATIENTS AND METHODS: We studied consecutive patients who had ORIF performed by a single surgeon for closed, intra-articular calcaneal fractures at our level-1 trauma center between 5/29/2012 and 3/20/2018. All inpatients were treated with a preoperative soft tissue management protocol, whereas outpatients were not. Data were obtained about demographic and clinical characteristics, times from injury to surgery, quality of fracture reductions, and complication rates. RESULTS: Mean follow-up for the 72 patients with 77 calcaneal fractures was 8.5 (range: 1-43) months, and 21 (27.3%) fractures received inpatient preoperative care with a soft tissue management protocol, while 56 (72.7%) received outpatient preoperative management. More of the fractures treated preoperatively as inpatients versus outpatients were classified as Sanders type III (66.7% vs. 32.1%) and type IV (8.9% vs. 4.8%) fractures and were associated with polytrauma (38.1% vs. 7.1%) and diabetes mellitus (9.5% vs. 5.4%), respectively. For all patients, the mean time from injury to surgery was 12.2 (range: 2.7-19.4) days, and the time was 6.3 days for inpatients and 14.4 days for outpatients, but the quality of fracture reductions and complication rates did not differ between these two groups. CONCLUSIONS: Patients with intra-articular calcaneal fractures treated as inpatients and receiving a preoperative soft tissue management protocol had outcomes after ORIF that were not inferior to those experienced by patients treated preoperatively as outpatients, despite a greater proportion of the inpatients having severe fractures, polytrauma, and diabetes mellitus. Dedicated preoperative soft tissue management protocols may be beneficial for patients with calcaneal fractures and warrant further study.

Postoperative wound complications in extensile lateral approach versus sinus tarsi approach for calcaneal fractures: Are we improving? Updated meta-analysis of recent literature.

INTRODUCTION: To analyze recent literature comparing clinical outcomes of displaced intra-articular calcaneal fractures (DIACF) treated with open reduction and internal fixation using the extensile lateral approach (ELA) vs the minimally invasive sinus tarsi approach (STA), with a focus on wound complications. MATERIALS AND METHODS: A comprehensive literature search was conducted utilizing PubMed, EMBASE, and Cochrane Library databases following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies published between 2013 and 2022, level of evidence (LOE) I-III, head-to-head comparative studies reporting on clinical outcomes after DIACFs treated with ORIF using ELA versus STA, and literature with full-text written in English were included. Data collection included: publication year, study design, number of surgeons, number of participants, demographic data (mean age at time of surgery, percent male, body mass index, medical co-morbidities), preoperative data (mechanism of injury, Sanders classification, time from injury to surgical fixation), intraoperative data, and postoperative clinical and radiographic outcomes (Böhler angle, angle of Gissane, calcaneal height/length/width). RESULTS: A total of 21 articles (4 randomized control trials, 17 cohort studies) comprising of 2086 patients with calcaneal fractures, treated with either ELA (n = 1129) or STA (n = 957) met inclusion criteria. The risk of postoperative wound-related complications (RR 2.82, 95 % CI: 2.00-3.98, I2=27 %) and the risk of reoperation (RR 1.85, 95 % CI: 0.69-5.00, I2=67 %) was higher in ELA patients comparted to STA patients. However, the increased risk of postoperative wound-related complications with an ELA vs. STA was shown to be trending downward in recent publications. The ELA group also experienced longer time to surgery, extended operative times, and prolonged hospital stays when compared to the STA group. Radiographic measurements at final follow-up, including Böhler angle, angle of Gissane, as well as calcaneal height, length, and width, showed no statistically significant differences between the two groups. CONCLUSION: Surgical treatment of calcaneal fractures utilizing the ELA continues to have an increased rate of complications and reoperation when compared to the less invasive STA, yet recent trends in the literature show that this rate is decreasing. Operative treatment of calcaneal fractures via either an ELA or STA can both achieve comparable postoperative radiographic outcomes. LEVEL OF EVIDENCE: Therapeutic Level III.

Current Management of Intra-Articular Calcaneal Fractures.

Intra-articular calcaneal fractures are debilitating injuries that can result in a dramatic effect on quality of life post-injury. Surgical intervention is generally advised when significant displacement or comminution is present but can present a host of complications secondary to the limited blood supply and fragility to the soft tissues following injury. Surgical approaches to calcaneal fractures generally include the lateral extensile approach, minimal incision (sinus tarsi approach), or percutaneous approach. Each approach presents risks and benefits; therefore, determining the optimal incisional approach should be based on patient comorbidities, fracture pathoanatomy, soft tissue envelope concerns, and patient pre-injury functional status.

Application of Human Acellular Dermal Matrix with Skin Graft for Lacunar Soft-Tissue Defect of Lateral Heel after Calcaneal Fracture.

OBJECTIVE: To investigate the clinical effect of human acellular dermal matrix (HADM) combined with split-thickness skin graft in repairing lacunar soft tissue defects of the lateral heel after calcaneal fracture. METHODS: From June 2018 to October 2020, providers repaired 11 cases of lacunar soft tissue defects at the lateral part of the heel using HADM combined with split-thickness skin graft. After thorough debridement, the HADM was trimmed and filled into the lacunar defect area. Once the wound was covered, a split-thickness skin graft and negative-pressure wound therapy were applied. Providers evaluated the appearance, scar, ductility of the skin graft site, appearance of the donor site, healing time, and any reoperation at follow-up. RESULTS: Of the 11 cases, 8 patients achieved successful wound healing by primary intention. Three patients showed partial necrosis in the edge of the skin graft, but the wound healed after standard wound care. Evaluation at 6 and 12 months after surgery showed that all patients had wound healing and mild local scarring; there was no obvious pigmentation or scar formation in the donor skin area. The average healing time was 37.5 days (range, 24-43 days). CONCLUSIONS: The HADM combined with split-thickness skin graft is a simple and effective reconstruction method for lacunar soft tissue defect of the lateral heel after calcaneal fracture. In this small sample, the combination demonstrated few infections, minor scar formation, few donor site complications, and relatively short hospital stays.

Comparison between intramedullary nail and conventional plate for displaced intra-articular calcaneal fractures: A meta-analysis.

OBJECTIVES: This study aimed to compare the efficacy and safety of the intramedullary nail and conventional plate for the treatment of displaced intra-articular calcaneal fractures from clinical comparative trials. MATERIALS AND METHODS: A comprehensive search of English databases was carried out in the Springer, PubMed, ScienceDirect, Web of Science, and Cochrane Library databases until September 2023. Studies on calcaneal fractures treated by an intramedullary nail or a plate were considered for inclusion. Endpoints included duration of operation, length of hospital stay, the Visual Analog Scale (VAS) score, postoperative functional score, radiological parameters, and complications. The mean difference (MD) and risk difference (RD) as the combined variables, as well as the 95% confidence intervals, (CIs) were calculated. RESULTS: Five retrospective controlled studies covering 473 feet at the one-year follow-up met the inclusion criteria. The meta-analysis demonstrated that there were significant differences in the duration of operation (MD: -10.81; 95% CI: -16.32, -5.31; p=0.0001), length of hospital stay (MD: -3.65; 95% CI: -4.35, -2.95; p<0.00001). No significant differences were found regarding postoperative American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale (MD: 0.36; 95% CI: -3.89, 4.61; p=0.87), VAS (MD: 1.95; 95% CI: -0.30, 4.21; p=0.09), or postoperative Böhler angle (MD: 0.94; 95% CI: -0.04, 1.92; p=0.06) between the two groups. The incidence of total complications (RD: -0.31; 95% CI: -0.46, -0.17; p<0.0001) and wound-healing complications (RD: -0.16; 95% CI: -0.30, -0.03; p=0.02) were lower in the intramedullary nail group. There were no significant differences in the incidences of revision surgery, implant removal, superficial wound infection, deep infection, and nonunion. CONCLUSION: Compared to conventional plates, the intramedullary nail showed a shorter duration of operation, reduced length of hospital stay, and fewer postoperative total complications and wound-healing complications in treating displaced intra-articular calcaneal fractures.

Hindfoot joint kinematics analysis after the resection of talocalcaneal coalition.

BACKGROUND: The subtalar joint movement between the talus and calcaneus is restricted in patients with talocalcaneal coalition (TCC). When the motion of the subtalar joint is restricted, shock absorption in the foot decreases, leading to pain during walking. Resection methods to maintain subtalar motion by removing abnormal unions have been proposed. The purpose of this study was to analyze the joint kinematics of patients who underwent TCC resection and to quantitatively evaluate the results of the surgery based on the measured kinematics. METHODS: Joint kinematics of five patients with TCC were obtained using a biplane fluoroscopic imaging system and an intensity-based two-/three-dimensional registration method. The joint kinematics of the tibiotalar and subtalar joints and the tibiocalcaneal motion during the stance phase of walking were obtained. From the kinematics of the hindfoot joints, the inversion/eversion range of motion (ROM) of the patients before and after resection was statistically analyzed using the Wilcoxon signed-rank test to test whether TCC resection improved the ROM. RESULTS: During the loading response period, the eversion ROM of the subtalar joint and tibiocalcaneal motion significantly increased postoperatively. In addition, a significant postoperative increase was observed in the subtalar and tibiocalcaneal inversion ROM during the pre-swing period. SIGNIFICANCE: TCC resection surgery increased the ROM of the subtalar joint, which in turn contributed to the increase in tibiocalcaneal ROM. Increased subtalar and tibiocalcaneal ROM could result in increased shock attenuation and may be a contributing factor to pain relief during walking.

[A prospective study on treatment of Sanders type â ¡ and â ¢ calcaneal fractures with interlocking intramedullary nail fixation system].

Objective: To explore the effectiveness of interlocking intramedullary nail fixation system for Sanders type Ⅱ and Ⅲ calcaneal fractures by comparing with open surgery. Methods: Forty patients (40 feet) with Sanders type Ⅱ and Ⅲ calcaneal fractures, who were admitted between May 2020 and December 2022 and met the selection criteria, were included in the study. They were randomly allocated into control group and minimally invasive group using a random number table method, with 20 cases in each group. The patients were treated with the interlocking intramedullary nail fixation system in the minimally invasive group and with steel plate internal fixation via a lateral L-shaped incision in the control group. There was no significant difference between the two groups ( P>0.05) in terms of gender, age, fracture classification and side, cause of injury, time from injury to admission, and preoperative width, length, height, Böhler angle, and Gissane angle of the calcaneus. The operation time, intraoperative blood loss, incision length, hospital stay, fracture healing time, incidence of complications, as well as pre- and post-operative imaging indicators (Böhler angle, Gissane angle, width, height, and length of the calcaneus) and American Orthopaedic Foot and Ankle Society (AOFAS) score of foot were recorded and compared between the two groups. Results: The incision length, operation time, and hospital stay of the minimally invasive group were significantly shorter than those of the control group, and the intraoperative blood loss significantly reduced ( P<0.05). All patients of the two groups were followed up, with the follow-up time of 8-12 months (mean, 10.2 months) in the minimally invasive group and 8-12 months (mean, 10.4 months) in the control group. No complication occurred in the minimally invasive group after operation. One case of incision epidermal necrosis and 1 case of traumatic arthritis occurred in the control group after operation. However, there was no significant difference in the incidence of complications between the two groups ( P>0.05). At last follow-up, the AOFAS score was significantly higher in the minimally invasive group than in the control group ( P<0.05). Imaging examination showed that the calcaneal fractures of the two groups healed, and there was no significant difference in healing time between the two groups ( P>0.05). Compared with preoperative conditions, the Böhler angle and Gissane angle of the calcaneus in the two groups significantly increased, the width narrowed, and the height and length increased at 3 days after operation and the last follow-up, with significant differences ( P<0.05). There was no significant difference between 3 days after operation and last follow-up ( P>0.05). There was no significant difference between the two groups at each time point ( P>0.05). Conclusion: The interlocking intramedullary nail fixation system in treatment of Sanders type Ⅱ and Ⅲ calcaneal fractures has the advantages of minimal trauma, shortened hospital stay, reliable fracture reduction and fixation, and satisfactory foot function recovery.

Design and Biomechanical Finite Element Analysis of Spatial Weaving Infracalcaneal Fixator System.

OBJECTIVE: Traditional internal fixation of calcaneus fractures, involving lateral L-shaped incisions and plate fixation, has disadvantages such as increased operative exposure, eccentric plate fixation, and complications. The aim of this study was to design a Spatial Weaving Intra-calcaneal Fixator System (SWIFS) for the treatment of complex calcaneal fractures and to compare its biomechanical properties with those of traditional calcaneal plates. METHODS: The computed tomography (CT) data of the normal adult calcaneus was used for modeling, and the largest trapezoidal column structure was cut and separated from the model and related parameters were measured. The SWIFS was designed within the target trapezoid, according to the characteristics of the fracture of the calcaneus. The Sanders model classification type IV calcaneal fracture was established in finite element software, and fixation with calcaneal plate and the SWIFS examined. Overall structural strength distribution and displacement in the two groups were compared. RESULTS: The maximum 3D trapezoidal column in the calcaneus was constructed, and the dimensions were measured. The SWIFS and the corresponding guide device were successfully designed. In the one-legged erect position state, the SWIFS group exhibited a peak von Mises equivalent stress of 96.00 MPa, a maximum displacement of 0.31 mm, and a structural stiffness of 2258.06 N/mm. The conventional calcaneal plate showed a peak von Mises equivalent stress of 228.66 Mpa, a maximum displacement of 1.26 mm, and a structural stiffness of 555.56 N/mm. The SWIFS group exhibited a 75.40% decrease in displacement and a 306.45% increase in stiffness. CONCLUSION: Compared with fixation by conventional calcaneal plate, the SWIFS provides better structural stability and effective stress distribution.

Beak-type fractures of the calcaneus.

Beak fractures represent a rare subtype of calcaneal fractures with potential risk of soft tissue complications due to compromised local perfusion. Early diagnosis and timely intervention are crucial to prevent necrosis, infection, and soft tissue defects. This case report describes a 71-year-old male with a beak fracture and delayed intervention with reoccurring soft tissue defects. Given the rarity of the condition, atypical presentation and need for urgent intervention, this emphasizes the importance of awareness of beak fractures of the calcaneus.

Intraosseous myolipoma of the calcaneus.

A man in his 40s presented with an incidental finding of an osteolytic bone lesion. He sustained an ankle injury while inline skating, fracturing his lateral malleolus. Besides the fracture, radiographic imaging on the day of the injury incidentally revealed a well-defined solitary osteolytic lesion with a sclerotic rim within the right calcaneus. MRI showed an intraosseous, fat-containing lesion with focal contrast enhancement, assessed as an intraosseous lipoma with central necrosis. In the pathological analysis of a sample of the lesion an intraosseous myolipoma of the calcaneus was found-an unexpected and extraordinary finding. To prevent pathological fracturing, curettage and bone grafting were performed using autologous iliac crest bone in combination with allogenous bone chips.

Lateralizing calcaneal osteotomy performed with a percutaneous burr results in a significantly lower increase in tarsal tunnel pressure.

PURPOSE: Tarsal tunnel syndrome is well documented following lateralizing calcaneal osteotomy to manage varus hindfoot deformity. Traditionally, calcaneal osteotomy is performed with an oscillating saw. No studies have investigated the effect of alternative surgical techniques on postoperative tarsal tunnel pressure. The purpose of this study was to investigate the difference in tarsal tunnel pressures following lateralizing calcaneal osteotomy performed using a high-torque, low-speed "minimally invasive surgery" (MIS) Shannon burr versus an oscillating saw. METHODS: Lateralizing calcaneal osteotomy was performed on 10 below-knee cadaveric specimens. This was conducted on 5 specimens each using an oscillating saw (Saw group) or MIS burr (Burr group). The calcaneal tuberosity was translated 1 cm laterally and transfixed using 2 Kirschner wires. Tarsal tunnel pressure was measured before and after osteotomy via ultrasound-guided percutaneous needle barometer. Mean pre/post-osteotomy pressures were compared between groups. Differences were analyzed using Student's t test. RESULTS: The mean pre-procedure tarsal tunnel pressure was 25.8 ± 5.1 mm Hg in the Saw group and 26.4 ± 4.3 mm Hg in the Burr group (p = 0.85). The mean post-procedure pressure was 63.4 ± 5.1 in the Saw group and 47.8 ± 4.3 in the Burr group (p = 0.01). Change in tarsal tunnel pressure was significantly lower in the Burr group (21.4 ± 4.5) compared to the Saw group (37.6 ± 12.5) (p = 0.03). The increase in tarsal tunnel pressure was 43% lower in the Burr group. CONCLUSION: In this cadaveric study, tarsal tunnel pressure increase after lateralizing calcaneal osteotomy was significantly lower when using a burr versus a saw. This is likely because the increased width ("kerf") of the 3 mm MIS burr, compared to the submillimeter saw blade width, causes calcaneal shortening. Given the smaller increase in tarsal tunnel pressure, using the MIS burr for lateralizing calcaneal osteotomy may decrease the risk of postoperative tarsal tunnel syndrome. Future research in vivo should explore this.

An investigation into the frequency and risk factors of low back pain following surgical treatment of isolated calcaneal fractures.

OBJECTIVE: This study aimed to determine the frequency of low back pain after calcaneal fractures treated with open reduction internal fixation (ORIF) and the risk factors that cause this condition. METHODS: Thirty-one patients (27 males and 4 females) who underwent surgery for a unilateral calcaneal fracture between 2016 and 2020 and had no complaints of low back pain before fracture surgery were included in the study. The patients were divided into 2 groups: those who developed low back pain after the operation and those who did not. Patients were evaluated with the Life Quality Short Form SF-36, the Oswestry Disability Index (ODI), and American Orthopedic Foot-Ankle Association Score (AOFAS). Sanders' fracture type, joint range of motion (ROM) measurements of injured and uninjured limbs, maximal isometric muscle strength measurements, balance on 1 leg with pedobarographic measurements, and walking time were evaluated. The obtained data were compared among the 2 groups. RESULTS: Low back pain was observed in 71% of the patients and was detected after an average of 6 months from the operation. In ODI, 59.1% of the patients reported that low back pain limited their lives slightly. Patients with low back pain have lower AOFAS scores and worse SF-36 physical functionality than those without low back pain (P < .001, P=.016). Balance time on 1 foot in pedobarographic measurements, foot in ROM, ankle in ankle active, passive plantar flexion, inversion, active hip, passive internal, external rotation, muscle is the foot eversion force. In these measurements, the values of the injured side are intact. It was statistically significantly lower than the other side (interaction P < .1). CONCLUSION: Low back pain may occur after unilateral calcaneal fractures treated by ORIF. This may be caused by decreased angles of ankle dorsi and plantar flexion, foot inversion, hip abduction, and internal and external rotation. In the rehabilitation program, not only the ankle region but also the hip joint of the affected side should be included, and the kinetic chain that describes the interaction mechanism of the human body should not be forgotten. LEVEL OF EVIDENCE: Level IV, Prognostic Study.

Impact of the medial displacement calcaneal osteotomy on foot biomechanics: a systematic literature review.

INTRODUCTION: Progressive collapsing foot deformity (PCFD), formally known as "adult-acquired flatfoot deformity" (AAFFD), is a complex foot deformity consisting of multiple components. If surgery is required, joint-preserving procedures, such as a medial displacement calcaneal osteotomy (MDCO), are frequently performed. The aim of this systematic review is to provide a summary of the evidence on the impact of MDCO on foot biomechanics. MATERIALS AND METHODS: A systematic literature search across two major sources (PubMed and Scopus) without time limitation was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) criteria. Only original research studies reporting on biomechanical changes following a MDCO were included. Exclusion criteria consisted of review articles, case studies, and studies not written in English. 27 studies were included and the methodologic quality graded according to the QUACS scale and the modified Coleman score. RESULTS: The 27 included studies consisted of 18 cadaveric, 7 studies based on biomechanical models, and 2 clinical studies. The impact of MDCO on the following five major parameters were assessed: plantar fascia (n = 6), medial longitudinal arch (n = 9), hind- and midfoot joint pressures (n = 10), Achilles tendon (n = 5), and gait pattern parameters (n = 3). The quality of the studies was moderate to good with a pooled mean QUACS score of 65% (range 46-92%) for in-vitro and a pooled mean Coleman score of 58 (range 56-65) points for clinical studies. CONCLUSION: A thorough knowledge of how MDCO impacts foot function is key in properly understanding the postoperative effects of this commonly performed procedure. According to the evidence, MDCO impacts the function of the plantar fascia and Achilles tendon, the integrity of the medial longitudinal arch, hind- and midfoot joint pressures, and consequently specific gait pattern parameters.

Biomechanical characteristics of Sanders type II and III calcaneal fractures fixed by open reduction and internal fixation and percutaneous minimally invasive fixation.

BACKGROUND: This work investigated the differences in the biomechanical properties of open reduction and internal fixation (ORIF) and percutaneous minimally invasive fixation (PMIF) for the fixation of calcaneal fractures (Sanders type II and III calcaneal fractures as examples) through finite element analysis. METHODS: Based on CT images of the human foot and ankle, according to the principle of three-point fixation, namely the sustentaculum tali, the anterior process and the calcaneal tuberosity were fixed. Three-dimensional finite element models of Sanders type II and III calcaneal fractures fixed by ORIF and PMIF were established. The proximal surfaces of the tibia, fibula and soft tissue were constrained, and ground reaction force and Achilles tendon force loads were added to simulate balanced standing. RESULTS: The maximum stress was 80.54, 211.59 and 113.88 MPa for the calcaneus, screws and plates in the ORIF group and 70.02 and 209.46 MPa for the calcaneus and screws in the PMIF group, respectively; the maximum displacement was 0.26, 0.21 and 0.12 mm for the calcaneus, screws and plates in the ORIF group and 0.20 and 0.14 mm for the calcaneus and screws in the PMIF group, respectively. The values obtained from the simulation were within the permissible stress and elastic deformation range of the materials used in the model, and there was no significant stress concentration. The maximum stress and displacement of the calcaneus and implants were slightly lower in the PMIF group than in the ORIF group when fixing Sanders type II and III calcaneal fractures. CONCLUSIONS: This study may provide a reference for optimising the design of implants, the development of individualised preoperative plans and the choice of clinical surgical approach.

[Arthroscopic Subtalar Distraction Arthrodesis in Post-Traumatic Indications]. / Artroskopická subtalární distrakcní artrodéza v poúrazových indikacích.

PURPOSE OF THE STUDY: This manuscript aims to present the method of arthroscopic assisted subtalar arthrodesis and to evaluate the benefi ts of this surgery on our study population. MATERIAL AND METHODS: In the period from 9/2007 to 1/2020, a total of 33 subtalar arthrodesis were performed in 31 patients aged 19-66 years (mean 48 years, median 50 years). The indication for arthrodesis was subtalar arthritis causing pain and gait disorders, or hindfoot deformities (most commonly after a calcaneus bone fracture). The arthroscopic assisted subtalar arthrodesis was performed with autologous tricortical bone block graft harvesting from the pelvis, supplemented by autologous cancellous bone graft. Stabilization was achieved by cannulated screws inserted in neutral ankle position. Patients in our retrospective study were followed up for a mean of 48 months (range, 24-130 months). The patients were evaluated preoperatively and at 2 years after surgery. The hindfoot angles and height (TCA - talocalcaneal angle, CIA - calcaneal inclination angle, TCH - talocalcaneal height) were evaluated on radiographs, bone union was assessed on radiographs and CT scans. The clinical assessment was performed using the ankle-hindfoot scale (AHS) of AOFAS (AOFAS score). RESULTS: The preoperative AOFAS score was 35-68 points (mean 52, median 54), the postoperative AOFAS score at 2 years after arthrodesis was 58-94 points (mean 82, median 82). Both the mean and median values of AOFAS score showed a signifi - cant progress from the poor result to the good and excellent result. After 2 years the TCA value decreased in 18 patients (56%) by no more than 3°. The CIA decrease observed in 21 patients (64%) was by 1° on average. The TCH decrease of 1-5 mm after 2 years since the surgery was seen in 16 patients. In 2 patients incomplete healing of arthrodesis was observed, manifested as a clinically asymptomatic non-union. No deep infection was reported. DISCUSSION: In agreement with the current literature, the arthroscopic subtalar arthrodesis has been confi rmed to be a safe method for the management of consequences of hindfoot fractures, with minimum complications and leading to accelerated bone fusion. Differences can be found in the approach, position, use of cancellous bone graft and surgical techniques. In recent years, prone position, posterior approaches, use of cancellous bone graft, distraction and fi xation with 2-3 screws divergently inserted into the bone prevail. The degree of healing of the bone fusion is generally an important factor. In our study population, non-healing was recorded in 2 patients, namely in the form of a clinically silent non-union. Neurological or early complications and/or osteosynthesis material failure occurred in up to a maximum of 10% of cases. The conclusive results of minimally invasive arthrodesis based on the AOFAS score have been confi rmed by us as well as by most authors. CONCLUSSIONS: Our study confi rmed that the arthroscopic assisted subtalar arthrodesis is a successful, reliable and safe minimally invasive method, with minimum complications, leading to stable arthrodesis. KEY WORDS: subtalar arthrodesis, subtalar arthroscopy.

Which implant is better for the fixation of posterior wall acetabular fractures: A conventional reconstruction plate or a brand-new calcaneal plate?

BACKGROUND: Increased posterior wall acetabular fractures among older adults, require precise treatment to restore stability to the joint, lower the risk of degenerative arthritis, and enhance overall functional recovery. The purpose of this study was to compare the fixation stability and mechanical characteristics of calcaneal buttress plate and conventional reconstruction plate under different loading condition. METHODS: Typical acetabular posterior wall fractures were created on twenty synthetic hemipelvis models. They were fixed with calcaneus plate and reconstruction plate. Dynamic and static tests were performed. Displacements of fracture line and stiffness were calculated. FINDINGS: After dynamic loading, calcaneus plate fixation has significantly less displacement than the reconstruction plate on the superior posterior wall. Under static loading condition, the calcaneus plate group has significantly less displacement than the reconstruction plate group on the inferior posterior part of the fracture. The average stiffness values of the calcaneus plate group and the reconstruction plate group were 265.16±53.98 N/mm and 167.48±36.87 N/mm, respectively and a statistically significant difference was found between the two groups. INTERPRETATION: The calcaneal plate group demonstrated better stability along the fracture line after dynamic and static loading conditions. Especially when the fragment was on the acetabulum's superior posterior, inferior posterior, and inferior rim, Calcaneal buttress plates offer biomechanically effective choices.

Impact of sustentaculum tali screw positioning on radiographic and functional outcomes in calcaneal fractures.

BACKGROUND: To investigate whether accurate placement of sustentaculum tali screws have the impacts on the clinical efficacy of calcaneal fractures. METHODS: A retrospective analysis of 72 cases (73 feet) of calcaneal fractures from September 2015 to September 2019 treated with open reduction and internal fixation with sustentaculum tali screws was conducted. Patients were divided into the sustentaculum tali fixation group (ST group) and the sustentaculum fragment fixation group (STF group) according to the location of the sustentaculum tali screw placement. The functional outcomes at preoperative, 7 days and 1 year postoperative were collected and analyzed. RESULTS: In the ST group (40 feet), the Gissane's angle altered from (109.89 ± 12.13)° to (121.23 ± 9.34)° and (119.08 ± 8.31)° at 7 days and 1 year postoperative, respectively. For Böhler's angles altered from (11.44 ± 5.94)°, to (31.39 ± 7.54)°, and (30.61 ± 7.94)° at 7 days and 1 year postoperative, respectively. In the STF group (33 feet), Gissane's angle altered from (110.47 ± 14.45)°, to (122.08 ± 8.84)°, and (120.67 ± 9.07)° and Böhler's angle altered from (11.32 ± 6.77)°, to (28.82 ± 8.52)°, and (28.25 ± 9.13)° (P < 0.001). However, there was no statistically significant difference in functional outcomes at 1 week after surgery and 1 year after surgery (P > 0.05). The AOFAS scores at the final follow-up of the two groups: ST group (88.95 ± 6.16) and STF group (89.78 ± 8.76); VAS scores, ST group (0.83 ± 0.98) and STF group (1.03 ± 1.59), all differences were not statistically significant (P > 0.05). CONCLUSION: The position of sustentaculum tali screws has no significant difference on the short-term clinical outcome in patients with calcaneal fractures, while reliable fixation of screws to sustentaculum tali fragment can achieve similar clinical outcome.

Biomechanical effects of Evans versus Hintermann osteotomy for treating adult acquired flatfoot deformity: a patient-specific finite element investigation.

BACKGROUND: Evans and Hintermann lateral column lengthening (LCL) procedures are both widely used to correct adult acquired flatfoot deformity (AAFD), and have both shown good clinical results. The aim of this study was to compare these two procedures in terms of corrective ability and biomechanics influence on the Chopart and subtalar joints through finite element (FE) analysis. METHODS: Twelve patient-specific FE models were established and validated. The Hintermann osteotomy was performed between the medial and posterior facets of the subtalar joint; while, the Evans osteotomy was performed on the anterior neck of the calcaneus around 10 mm from the calcaneocuboid joint surface. In each procedure, a triangular wedge of varying size was inserted at the lateral edge. The two procedures were then compared based on the measured strains of superomedial calcaneonavicular ligaments and planter facia, the talus-first metatarsal angle, and the contact characteristics of talonavicular, calcaneocuboid and subtalar joints. RESULTS: The Hintermann procedure achieved a greater correction of the talus-first metatarsal angle than Evans when using grafts of the same size, indicating that Hintermann had stronger corrective ability. However, its distributions of von-Mises stress in the subtalar, talonavicular and calcaneocuboid joints were less homogeneous than those of Evans. In addition, the strains of superomedial calcaneonavicular ligaments and planter facia of Hintermann were also greater than those of Evans, but both generally within the safe range (less than 6%). CONCLUSION: This FE analysis study indicates that both Evans and Hintermann procedures have good corrective ability for AAFD. Compared to Evans, Hintermann procedure can provide a stronger corrective effect while causing greater disturbance to the biomechanics of Chopart joints, which may be an important mechanism of arthritis. Nevertheless, it yields a better protection to the subtalar joint than Evans osteotomy. CLINICAL RELEVANCE: Both Evans and Hintermann LCL surgeries have a considerable impact on adjacent joints and ligament tissues. Such effects alongside the overcorrection problem should be cautiously considered when choosing the specific surgical method. LEVEL OF EVIDENCE: Level III, case-control study.