Acromioclavicular joint suture button repair leads to coracoclavicular tunnel widening.

PURPOSE: Biomechanical evaluation of three different suture button devices used in acromioclavicular joint repair and analysis of their effect on post-testing tunnel widening. METHODS: Eighteen human shoulder girdles were assigned into three groups with a similar mean bone mineral density. Three different single-tunnel acromioclavicular repair devices were tested: (1) AC TightRope® with FiberWire; (2) AC Dog Bone™ Button with FiberTape; (3) Low Profile AC Repair System. Biomechanical testing was performed simulating the complex movement of the distal clavicle as follows. A vertical load of 80 N was applied continuously. The rotation of the clavicle about its long axis was set at 10° anterior and 30° posterior for 2500 cycles at 0.25 Hz. The horizontal translation of the clavicle was set at 6 mm medial and 6 mm lateral for 10,000 cycles at 1 Hz. The coracoclavicular distance was measured before and after testing. After testing, each sample underwent micro-CT analysis. Following 3D reconstruction, the area of the bone tunnels was measured at five defined cross sections. RESULTS: In TightRope® and Dog Bone™ groups, all samples completed testing, whereas in the Low Profile group, three out of six samples showed system failure. The mean absolute difference of coracoclavicular distance after testing was significantly greater in the Low Profile group compared to TightRope® and Dog Bone™ groups (4.3 ± 1.3 mm vs 1.9 ± 0.7 mm vs 1.9 ± 0.8 mm; p = 0.001). Micro-CT analysis of the specimens demonstrated significant tunnel widening in the inferior clavicular and superior coracoid regions in all three groups (p < 0.05). CONCLUSION: Significant tunnel widening can be observed for all devices and is primarily found in the inferior parts of the clavicle and superior parts of the coracoid. The Low Profile AC Repair System showed inferior biomechanical properties compared to the AC TightRope® and AC Dog Bone™ devices. Therefore, clinicians should carefully select the type of acromioclavicular repair device used and need to consider tunnel widening as a complication.

All-suture anchor pullout results in decreased bone damage and depends on cortical thickness.

PURPOSE: To evaluate the influence of cortical and cancellous bone structure on the biomechanical properties of all-suture and conventional anchors and compare the morphological bone damage after their failure. The hypothesis of the study is that all-suture anchor pullout is less invasive and that the pullout force is influenced by the cortical thickness. METHODS: Thirty human humeri were biomechanically tested as follows: starting with a load cycle from 20 to 50 N, a stepwise increase of the upper peak force by 0.05 N for each cycle at a rate of 1 Hz was performed. Analysis included maximum pullout strength for three different anchor implantation angles (45°, 90°, 110°) of the two anchor types. After anchor pullout, every sample underwent micro-CT analysis. Bone mineral density (BMD) and cortical thickness were determined at the anchor implantation site. Furthermore, the diameter of the cortical defect and the volume of the bone cavity were identified. RESULTS: The maximum pullout strength of all-suture anchors demonstrates a strong correlation to the adjacent cortical thickness (r = 0.82, p ≤ 0.05) with at least 0.4 mm needed to withstand 200 N. No correlation could be seen in conventional anchors. Moreover, no correlation could be detected for local BMD in both anchors. All-suture anchors show a significantly narrower cortical defect as well as a smaller bone cavity following pullout (4.3 ± 1.3 mm vs. 5.3 ± 0.9 mm, p = 0.037; 141 mm3 vs. 212 mm3; p = 0.009). The cortical defect is largest if the anchors are placed at a 45° angle. CONCLUSION: In contrast to conventional anchors, the pullout force of all-suture anchors depends on the thickness of the humeral cortex. Furthermore, all-suture anchors show a significantly smaller cortical defect as well as decreased bone damage in the case of pullout. Therefore, the clinical implication of this study is that all-suture anchors are advantageous due to their bone preserving ability. Also, intraoperative decortication should not be performed and cortical thickness should be preoperatively evaluated to decrease the risk of anchor failure.

Biomechanical comparison of polylactide-based versus titanium miniplates in mandible reconstruction in vitro.

OBJECTIVES: Evaluation of the mechanical integrity and reliability of polylactide-based miniplates for osseous free flap fixation at the mandible in an experimental study setup of a mandible reconstruction model. MATERIAL AND METHODS: 1.0mm titanium miniplates (group TI) (MatrixMandible, DePuy Synthes, Umkirch, Germany) and 1.5mm polylactide miniplates (group PL) (Inion CPS, Inion Oy, Tampere, Finland) were used to fix a polyurethane (PU) fibula segment to a PU mandible reconstruction model using monocortical non-locking screws. Mastication was simulated via unilateral cyclic dynamic loading at 1Hz with increasing loads (+ 0.15N/cycle, Bionix, MTS, USA). A 3D optical tracking system (Aramis, GOM, Braunschweig, Germany) was used to determine interosteotomy movements (IOM). RESULTS: IOM were higher in the polylactide group (distal: P=0.001, mesial: P=0.001). Differences in mean stiffness (titanium: 478±68N/mm; polylactide: 425±38N/mm, P=0.240) and mean force at a vertical displacement of 1.0mm (titanium: 201.6±87.1N; polylactide: 141.3±29.9N, P=0.159) were not significant. CONCLUSIONS: The results of this study suggest that polylactide-based miniplates provide reduced mechanical integrity and higher interosteotomy movements in comparison to titanium miniplates in vitro. Indications for clinical use of polylactide-based miniplates in mandible reconstruction have to be placed critically. Future studies will focus on clinical complications of polylactide-based plates in risk patients.

A calcar collar is protective against early periprosthetic femoral fracture around cementless femoral components in primary total hip arthroplasty: a registry study with biomechanical validation.

AIMS: The aim of this study was to estimate the 90-day risk of revision for periprosthetic femoral fracture associated with design features of cementless femoral stems, and to investigate the effect of a collar on this risk using a biomechanical in vitro model. MATERIALS AND METHODS: A total of 337 647 primary total hip arthroplasties (THAs) from the United Kingdom National Joint Registry (NJR) were included in a multivariable survival and regression analysis to identify the adjusted hazard of revision for periprosthetic fracture following primary THA using a cementless stem. The effect of a collar in cementless THA on this risk was evaluated in an in vitro model using paired fresh frozen cadaveric femora. RESULTS: The prevalence of early revision for periprosthetic fracture was 0.34% (1180/337 647) and 44.0% (520/1180) occurred within 90 days of surgery. Implant risk factors included: collarless stem, non-grit-blasted finish, and triple-tapered design. In the in vitro model, a medial calcar collar consistently improved the stability and resistance to fracture. CONCLUSION: Analysis of features of stem design in registry data is a useful method of identifying implant characteristics that affect the risk of early periprosthetic fracture around a cementless femoral stem. A collar on the calcar reduced the risk of an early periprosthetic fracture and this was confirmed by biomechanical testing. This approach may be useful in the analysis of other uncommon modes of failure after THA. Cite this article: Bone Joint J 2019;101-B:779-786.

Factors influencing taper failure of modular revision hip stems.

Stem modularity of revision hip implant systems offers the advantage of the restoration of individual patient geometry but introduces additional interfaces, which are subjected to repetitive bending loading and have a propensity for fretting corrosion. The male stem taper is the weakest part of the modular junction due to its reduced cross section compared to the outside diameter of the stem. Taper fractures can be the consequence of overloading in combination with corrosion. The purpose of this study was to assess the influence of implant design factors, patient factors, and surgical factors on the risk of taper failure of the modular junction of revision stems. An analytical bending model was used to estimate the strength of the taper connection for pristine, fatigued and corroded conditions. Additionally, a finite element contact model of the taper connection was developed to assess the relative motion and potential for surface damage at the taper interface under physiological loading for varyied assembly and design parameters. Increasing the male taper diameter was shown to be the most effective means for increasing taper strength but would require a concurrent increase in the outer implant diameter to limit a greater risk of total surface damage for a thinner female taper wall. Increasing the assembly force decreases the total surface damage but not local magnitudes, which are probably responsible for crack initiation. It is suggested that in unfavourable loading conditions a monobloc implant system will reduce the risk of failure.

Clinical and Wear Analyses of 9 Large Metal-on-Metal Total Hip Prostheses.

BACKGROUND: Metal-on-Metal (MoM) total hip arthroplasties (THA) are associated with pseudotumor formation and high revision rates. This prospective study analysed the clinical and wear analyses of 9 large Metal-on-Metal (MoM) total hip arthroplasties (THA) to understand the underlying mechanisms of failure. The MoM bearings were revised for multiple reasons; the main reason was pseudotumor formation. MATERIALS AND METHODS: From 2006 till 2010 the Reinier de Graaf Hospital implanted 160 large head M2a-Magnum™ (Biomet Inc. Warsaw, Indiana, USA) THAs in 150 patients. The first year, 9 bearings were revised and analysed at the Biomechanics Section, Hamburg University of Technology, Germany. We performed clinical (Harris Hip Score, radiographic analysis, blood cobalt and chromium) and wear analysis (implant, tissue and fluid) of the 9 bearings. Since this study did not fall under the scope of the Medical Research Involving Human Subjects Act in The Netherlands, no ethical approval was necessary. In this prospective study all patient details were anonymized by the corresponding author, all other authors were blinded during the research and wear analyses. Patients with bilateral MoM implants were excluded. RESULTS: The 9 bearings had a median (IQR) survival of 41.0 (25) months in situ. From these bearings, three showed no noticeable wear. The median (IQR) head wear volume was 3.2 (3.6) mm3 and maximum wear depth 0.02 (0.02) mm. For the cup the median (IQR) wear volume was 0.23 (0.3) mm3 with a maximum wear depth of 0.03 (0.05) mm. CONCLUSION: An early identification of parameters related to failure of the MoM THA, such as pain, decreased range of motion, radiographic changes and high levels of blood cobalt and chromium is of great importance for patient's quality of life. Especially now patients and surgeons face the long term effects of all these bearings still in situ. This study reports the clinical and wear analyses of 9 MoM THA. In the majority of this group the reason for revision was pseudotumor formation. Most bearings showed signs of wear, however with a great diversity in clinical analysis, in inclination angle, serum cobalt and chromium levels as well as wear analysis. For a better understanding of the underlying mechanisms related with failure, more wear analyses of revised MoM bearings are necessary as well as a frequent follow-up of the patients with a MoM bearing.

Severe Wear and Pseudotumor Formation Due to Taper Mismatch in a Total Hip Arthroplasty: A Case Report.

CASE: We describe the case of a seventy-six-year-old woman who had undergone bilateral total hip arthroplasty with Zweymüller-Metasul prostheses in 1996. After a fall sixteen years after the index procedures, radiographs suggested a taper fracture of the left total hip arthroplasty. However, revision surgery showed pseudotumor formation, with no evidence of taper fracture. Analysis of the prosthesis showed massive wear of the male stem taper caused by a mismatch between the stem taper and the head taper. CONCLUSION: This case vividly demonstrates how taper size mismatch can cause dramatic metal wear and increased release of metal ions, resulting in pseudotumor formation.

The relation between titanium taper corrosion and cobalt-chromium bearing wear in large-head metal-on-metal total hip prostheses: a retrieval study.

BACKGROUND: Revision of hip implants due to adverse tissue reactions to metal debris has been associated with wear and corrosion of the metal-on-metal bearing articulation and the modular taper interface. Bearing articulation wear is increased in conditions of poor lubrication, which can also lead to high friction moments that may cause corrosion at the taper interface. This suggests that wear of the bearing and increased corrosion of the taper interface should occur simultaneously, which was investigated in this study. METHODS: Forty-three large-diameter cobalt-chromium bearings of the same design, implanted with a titanium stem using a titanium adapter, were retrieved at revision at a single center. Retrievals were grouped according to visual inspection of the female taper surface of the adapter into slight and severe corrosion groups. Volume change of bearing and taper surfaces was assessed using a coordinate measurement machine. Serum ion concentrations were determined for forty-three patients, whereas tissue metal concentration was measured for twelve patients. RESULTS: Severe taper corrosion was observed in 30% of the retrievals. Corrosion was observed either as material deposition or wear. The overall bearing wear rate was significantly higher in the group with severe taper corrosion than in the group with slight corrosion (7.2 ± 9.0 mm(3)/yr versus 3.1 ± 6.8 mm(3)/yr, respectively; p = 0.023) as were the serum cobalt (40.5 ± 44.9 µg/L versus 15.2 ± 23.9 µg/L, respectively; p = 0.024) and chromium ion concentrations (32.7 ± 32.7 µg/L versus 12.0 ± 15.1 µg/L, respectively; p = 0.019). Serum metal ion concentrations were more consistent indicators of wear than tissue metal concentrations. CONCLUSIONS: The increased bearing articulation wear and serum metal ion concentrations in cases with taper interface corrosion support the hypothesis that increased friction in the joint articulation is one of the factors responsible for simultaneous articulation and taper damage. However, independent taper or bearing damage was also observed, suggesting that other factors are involved in the process.

Periprosthetic tissue metal content but not serum metal content predicts the type of tissue response in failed small-diameter metal-on-metal total hip arthroplasties.

BACKGROUND: Tissue responses to periprosthetic metal wear debris are complex and poorly understood. There are two predominant tissue responses: a nonspecific macrophage-mediated granulomatous response and lymphocyte-dominated response, which has immunological memory and is mediated by T cells. Delayed hypersensitivity-type responses may accelerate aseptic loosening of arthroplasty implants. We hypothesized that the metal content of periprosthetic tissue but not of serum would be predictive of the type of tissue response to metal wear debris. METHODS: We examined twenty-eight total hip arthroplasty implant retrievals from twenty-seven patients who had undergone revision arthroplasty at one institution. Indications for revision were pain and/or osteolysis; one patient had recurrent dislocations. Tissue samples were analyzed microscopically and the metal (Co, Cr, and Ni) content was determined. Explanted prosthetic components were examined for linear wear. Intraoperatively, periprosthetic metallosis was observed in twelve cases and formation of a bursa (pseudotumor) was observed in thirteen. The acetabular cup was loose in eleven cases, the femoral stem was loose in five, and both components were loose in five. RESULTS: The metal (Co, Cr, and Ni) content of the periprosthetic tissue ranged from 1.4 to 4604.0 µg/g. Histologically, macrophages containing metal particles as well as diffuse and perivascular lymphocytic infiltration were observed. Fibrin exudation was also visible. Tissues that displayed a predominantly lymphocytic response had a mean metal content of 222.2 ± 52.9 µg/g, whereas those that displayed a macrophage-dominated response had a metal content of 3.0 ± 0.9 µg/g; this difference was significant (p = 0.001). The mean serum metal content did not differ significantly between the two subgroups (60.7 ± 13.4 compared with 43.7 ± 3.8 µg/L, p = 0.105). CONCLUSIONS: An association between periprosthetic tissue metal content and hypersensitivity appears likely but needs to be validated with larger-scale retrieval studies. CLINICAL RELEVANCE: This study contributes to the understanding of tissue responses to metal wear debris after joint replacement and the factors that are predictive of a type-IV lymphocyte-dominated hypersensitivity reaction.

[Squeaking as a cause for revision of a composite ceramic cup]. / Quietschen als Revisionsursache einer Kompositkeramikpfanne.

Squeaking in total hip arthroplasty (THA) has been observed only in hard-on-hard bearings, such as ceramic-on-ceramic or metal-on-metal. We report the case of a patient with a squeaking THA who had undergone multiple femoral head revisions combined with a composite ceramic cup (polyurethane, ceramic). Squeaking started 6 years postoperatively and acetabular revision was necessary to resolve the issue. Secondary deformation of the inlay resulted in clamping of the femoral head and increased friction. This should be considered when assessing and advising patients with squeaking THA when composite ceramic components are involved.

[Damage to a hip endoprosthesis caused by high-frequency electrocautery]. / Schädigung eines Hüftendoprothesenschafts durch Einsatz eines Hochfrequenzmessers.

Contact between high-frequency cauterising instruments and metal endoprostheses can cause visible flashovers. The resulting local heating might partially transform the microstructure of the prostheses. In the present case a flashover to the in situ titanium hip endoprosthesis during the revision of a fractured ceramic head decreased the fatigue strength of the prosthesis and ultimately caused its failure. During revision surgery it is essential to prevent contact between in situ metal components and high-frequency cauterising instruments.

[Reasons for failure of hip resurfacing implants. A failure analysis based on 250 revision specimens]. / Versagensgründe von Oberflächenersatzimplantaten der Hüfte. Eine Analyse von 250 Revisionspräparaten

Hip resurfacing has been experiencing a revival over the last 5-10 years. Early failure rates are higher than for conventional primary hip arthroplasty. Fractures of the femoral neck or head, cup loosening and persistent pain are the most frequently observed reasons for early revision. In this international retrospective uncontrolled study, 256 revision specimens (219 resurfacing heads, 37 cups) were analysed radiologically, tribologically, morphologically and histologically in order to investigate the failure mechanism. Of the head revisions, 70% were due to neck (median: 67 days after implantation) and head fractures (161 days), 9% were due to cup loosening (350 days) and 21% due to other reasons (602 days). Implants with rim loading (22% of all retrievals, cup inclination 58.0+/-10.9 degrees ) exhibited a head wear rate of 7.1+/-5.2 mm3/year. Non-rim loaded implants exhibited a head wear rate of 0.24+/-0.53 mm3/year (cup inclination 49.0+/-4.0 degrees ). The failure rate was highest during the first 16 weeks after surgery and for the first ten operations performed by a surgeon. Revisions based on problems on the femoral side such as notching and high implantation forces occurred earlier than revisions based on problems on the acetabular side such as cup loosening and high wear due to suboptimal cup position.

Biomechanical, morphological, and histological analysis of early failures in hip resurfacing arthroplasty.

The present revival of hip resurfacing arthroplasty may be related to an increase in early failures owing to the challenging technique of the procedure. Fifty-five retrieved implants were analysed with respect to wear, cement mantle and cement penetration, fracture and head morphology, as well as standard histology. Femoral neck fractures occurred in median after 102 days. The time to failure was shorter for older women. Major deviations from the suggested cement mantle thickness and cement penetration were found. Indications for high trauma during implantation leading to early failure due to weakening of the femoral neck were also observed. Some failures had signs of pseudarthrosis beneath the implant. Four different fracture patterns with different mean survival times were identified. Observed wear was minor with the exception of that due to alignment mistakes (rim loading). The cups were not damaged by the failures. Histological results indicate that avascular necrosis is not necessarily connected with this kind of endoprosthetic surgery. Most of the failures analysed can probably be attributed to the 'learning curve' effect, which is an unsatisfactory situation.

Lessons learned from early clinical experience and results of 300 ASR hip resurfacing implantations.

Between August 2003 and April 2005, 300 ASR metal-on-metal resurfacing hip endoprostheses were implanted by the first author and a fellow surgeon. The mean age at surgery was 56.8 years (18-75.9 years) and mean body mass index was 27.6 kg/m2 (range, 19-41 kg/m2). The mean follow-up time was 202 days. The mean Harris hip score improved from 44 pre-operatively to 89 at 3 months post-operatively. In total, eight (2.7 per cent) cases [five neck fractures (1.66 per cent) and three cup revisions (1 per cent)] were revised. Two neck fractures occurred within a group of seven cases of femoral neck notching detected postoperatively; one neck fracture occurred out of two cases of incomplete seating of the femoral implant. A significantly higher (p < 0.001) failure rate was observed for patients who had undergone a previous osteosynthesis of the proximal femur (three revisions in a group of 15 patients). Revision cases had a significantly greater body mass index (p = 0.031). A learning curve was evident from the reduction in revisions from 5 in the first 100 surgical procedures to 2 in the next 100 and 1 in the last 100. These results show the importance of accurate surgical technique and careful patient selection for fourth-generation hip resurfacing implants,

Migration of two different cementless hip arthroplasty stems in combination with two different heads: a biomechanical in vitro study.

The aim of the present in vitro study was to evaluate migrational characteristics of cementless primary hip arthroplasty stems in combination with a diameter 50 mm head (hemiarthroplasty) and a diameter 28 mm head in and with a polyethylene cup (total hip arthroplasty) in fresh-frozen human specimens. Two different types (Endo SL, FMT) were implanted into seven pairs of fresh-frozen human femoral specimens. The implanted stems were combined with a diameter 50 mm head (hemiarthroplasty) on one side and with a polyethylene cup and a 28 mm head (total hip arthroplasty) on the other side. Dynamic mechanical loading was applied for 50,000 cycles while recording relative motions between stem and bone stock using a 3-D motion analysis system. The Endo SL stem showed a significantly higher amplitude of relative motion in all translational and rotational components regardless of the head used. In both stem types a strong tendency for higher axial migration with the diameter 50 mm head in comparison to the THA head was found. The lowest axial migration was found in the FMTstem in combination with the small head and a PE cup. The highest axial migration was found in the Endo SL stem combined with the diameter 50 mm head. Our results indicate that the head might play an important role for axial migration of cementless stems.

[Comparison of total hip replacements cup orientation and position. Navigation vs. conventional manual implantation of hip prostheses]. / Pfannenposition und Orientierung im Vergleich. Navigation vs. konventionelle Handimplantion von Hüftendoprothesen.

BACKGROUND: Aim of this in-vitro study was to compare the hip cup placement for total hip replacement when using different navigation systems compared with the traditional, non-navigated technique. METHODS: Five different navigation systems were used: the CT-less systems Navitrack, Orthopilot and Surgetics Station, as well as the CT-based Navitrack and VectorVision. Three different surgeons carried out five cup implantations using all navigation systems and the manual approach on a surgery dummy. Cup orientation (inclination and anteversion) and the cup position (achieved cup center) were determined with a coordinate measuring machine. RESULTS: In the manual group the variability of the cup orientation was higher in comparison and hardly influenced by the surgeon. Navigation was identified as a significant factor for smaller deviations from planned inclination and anteversion angles (p<0,001 for both). Cup position was not affected by surgeon in the manual group (p=0,966). Compared with manual technique, the cup misplacement vector was significantly smaller in the CT-Navitrack group (p<0,001) but higher in the Navitrack (CT-less) and VectorVision group (p<0,001). CONCLUSIONS: The use of computer navigation will help the surgeon to orientate the acetabular component more accurately but not necessarily with regard to cup positioning.

The influence of friction and interference on the seating of a hemispherical press-fit cup: a finite element investigation.

The formation of gaps in the polar region of acetabular cups is seen as a drawback of press-fit fixation of non-cemented acetabular cups. Recent findings indicate a link between long-term polar gaps and the gaps present directly after implantation. In this study the process of press-fitting is simulated with a linear-elastic two-dimensional axisymmetric finite-element model. The aim of this paper is to investigate the possible importance of friction and interference on the formation of these gaps. A range of cup-bone friction coefficients (mu = 0.1-0.5) is assigned to the cup-bone interface in order to represent the unknown amount of friction occurring during press-fitting. The cup is modeled with a radius of 27 mm, whereas the radius of the cavity is varied between 26.50 and 26.75 mm, thus, creating 0.50 and 0.25 mm radial interference fits. The difference in cavity radius represents the discrepancy between the radius of the last-reamer-used and radius of the cavity it creates. The subchondral plate is considered as being completely removed during reaming. The effects of impact blows via the surgeon's mallet during surgery are modeled as a series of four load pulses, in which peak force is gradually increased from 0.5 to 4.0 kN. The effects of load removal as well as those of load application are investigated. On load application, the cup penetrates into the cavity, and on load removal, the cup rebounds. Depending on the friction, interference and load applied, the position of the cup after the load pulse is somewhere between its position at peak force and its position at the beginning of the pulse. Although the simplifications and conditions involved in the creation of the model necessitate caution when interpreting the results for all clinical cases, it is found that the seating of hemispherical cups in trabecular bone could be more satisfactory for intermediate values of friction (mu = 0.2-0.3) and smaller interference fits (0.25 mm).

Analysis of morphology and gait function after intraarticular calcaneal fracture.

Open reduction and internal fixation is suggested by an increasing number of investigators as preferable treatment of displaced intraarticular calcaneal fractures. Assuming that quasianatomical reduction coincides with adequate function, many surgeons rely on morphological parameters (standard radiography, computed tomography) to demonstrate the effectiveness of surgery by achieving an optimum restoration of calcaneal geometry and joint surfaces. In order to correlate morphologic parameters and functional assessment, a prospective study was performed on 45 patients after surgical treatment of intraarticular calcaneal fractures using standard radiographic and computed tomographic scores, clinical evaluation, and gait analysis (dynamic pedography). Mean follow-up time after reconstruction was 23 months (range 18-50). Although clinical evaluation and assessment of gait function corresponded well with each other, radiographic scores showed a poor to moderate correlation with functional evaluation (r = 0.29-0.62); this was probably due to the missing analysis of soft tissue parameters. The comparison of clinical results and gait parameters with the individual radiographical parameters allowed us to identify those factors, with the greatest influence seen on the functional prognosis (i.e., calcaneal width, arthrosis in the neighboring joints). Morphologic analysis after calcaneal reconstruction based on radiographic techniques cannot predict subsequent function or substitute for functional assessment. However, it does allow for practical conclusions for surgical strategy in primary osseous reconstruction or secondary corrections.