Between January 2003 and December 2004, 14 patients underwent bilateral resurfacing arthroplasty via a Ganz trochanteric osteotomy. This bilateral group was mobilised fully weight-bearing with crutches. During the same period 139 Ganz trochanteric osteotomies were performed for unilateral hip resurfacing. These patients were mobilised with crutches, weight-bearing up to 10 kg on the operated leg. Nine osteotomies (32%) in the bilateral group subsequently developed a symptomatic non union requiring revision of fixation. This compares with 10 patients (7%) in the unilateral group. Applying the Fisher’s exact test, the difference reached significance (p=0.0004). In 2 patients a second revision was required to achieve union. In 1 patient, revision of trochanteric fixation precipitated a deep infection. Protected weight-bearing following a Ganz trochanteric osteotomy is important to the success of the procedure. Simultaneous bilateral hip arthroplasty through a Ganz approach should be avoided. If it is undertaken, we recommend that patients should be non weight-bearing for 6 weeks following surgery. Non union following a Ganz trochanteric osteotomy for arthroplasty carries a significant morbidity

Ganz's studies made it possible to address joint deformities on both femoral and acetabular side brought by the Legg-Calvè-Perthes disease (LCPD). Femoral head reduction osteotomy (FHRO) was developed to improve joint congruency along with periacetabular osteotomy (PAO). The purpose of this study is to show the clinical and morphologic outcomes of the technique, and an implemented planning approach. From 2015 to 2023, 13 FHROs were performed on 11 patients for LCPD, in two centers. 11 of 13 hips had an associated PAO. A specific CT and MRI-based protocol for virtual simulation of the corrections was developed. Outcomes were assessed with radiographic parameters (sphericity index, extrusion index, integrity of the Shenton's line, LCE angle, Tonnis angle, CCD angle) and clinical parameters (ROM, VAS, Merle d'Aubigné-Postel score, modified-HHS, EQ5D-5L). Early and late complications were reported. The mean follow-up was 40 months. The mean age at surgery was 11,4 years. No major complications were recorded. One patient required a total hip arthroplasty. Femoral Head Sphericity increased from 45% to 70% (p < 0,001); LCE angle from 18° to 42,8° (p < 0,001); extrusion Index from 36,6 to 8 (p < 0,001); Tonnis Angle from 14,4° to 6,2° (p = 0.1); CCD Angle from 131,7 to 136,5° (p < 0,023). The VAS score improved from 3,25 to 0,75,(p = 0.06); Merle d'Aubigné-Postel score from 14.75 to 16 (p = 0,1); Modified-HHS from 65,6 to 89,05 (p = 0,02). The EQ 5D 5L showed significant improvements. ROM increased especially in abduction and extra-rotation. FHRO associated with periacetabular procedures is a safe technique that showed improved functional, clinical and morphologic outcomes in LCPD. The newly introduced simulation and planning algorithm may help to further refine the technique

Narrowing of the femoral neck after resurfacing arthroplasty of the hip has been described previously in both cemented and uncemented hip resurfacing. Traditionally hip resurfacing has been performed via a posterior approach though other surgical approaches including the Ganz and the anterolateral approach have been well described. In addition it is known that the blood supply of the femoral neck arises largely from posterior structures and it has been postulated that neck narrowing is a consequence of poor post-operative femoral neck vascularity. Our null hypothesis in this study was that the choice of surgical approach does not influence postoperative femoral neck narrowing. We retrospectively measured the diameter of the femoral neck in a series of 135 consecutive patients who underwent uncemented cormet hip resurfacing, with follow up from one to 3 years. Our sample included 50 females and 85 men with an average age of 56.4 years (standard deviation of 9.47). Seventy six patients had a Ganz approach, 5 had an anterolateral approach and 55 had a posterior approach. There were no failures due to femoral neck fracture and no revisions to total hip arthroplasty. Eleven patients required subsequent surgery all of which were due to complications following trochanteric osteotomy. Seven patients needed removal of metalwork and 4 patients had non-union of their osteotomy requiring revision. At one year the posterior approach group had an average of 5.2% neck narrowing versus 2.7% neck narrowing in the Ganz approach group (p value 0.06). At three years the average neck narrowing amongst all patients was 6.8% (standard deviation 3.1%) but the number of patients who had had a Ganz approach was too small to meaningfully apply inference statistics. Our study shows early results which show a statistically significant reduction in the rate of femoral neck narrowing in patients who have had a Ganz approach as compared to a posterior approach for unce-mented hip resurfacing arthroplasty. It also shows a high rate of complications inherent with the Ganz approach which in our patient group are entirely related to the trochanteric osteotomy

This case series highlights the use of the Ganz approach (trochanteric slide approach) and surgical dislocation for excision of fibrous dysplasia of the femoral neck, pigmented villonodular synovitis and synovial chondromatosis of the hip. The first patient was a 16-year-old girl, who presented with pain in her hip, having fallen whilst playing football. Investigations revealed a fibrous dysplasia, which was successfully excised returning her to an active lifestyle. The second patient was a 27-year-old lady, who presented having suffered left hip pain for four years. She was diagnosed with a pigmented villonodular synovitis, which was excised and the patient was able to return to the gym. The third patient was a 41-year-old lady, who presented after experiencing right hip pain both at night and at rest for a year, without any trauma. She was diagnosed with synovial chondromatosis and returned to all activities of daily living. The Ganz approach allows safe dislocation of the hip joint without the risk of osteonecrosis of the femoral head. We demonstrate that it is possible to obtain excellent exposure of the femoral neck, head and acetabulum to surgically treat these three tumours of the hip. The surgeon can thus be reassured that complete excision of the tumour has occurred. This series can recommend the Ganz approach with trochanteric slide and full surgical dislocation of the hip to excise pigmented villonodular synovitis, synovial chondromatosis and fibrous dysplasia of the hip

A prospective study was done on 6 adolescent patients with severe unilateral chronic SCFE who underwent femoral neck cuneiform osteotomies with an antero lateral Ganz approach and subsequent anterior hip dislocation. Patients with chronic SCFE, open growth plates and Southwick diaphyseal epiphyseal angle of more than 60 degrees were selected. In situ pinning was not possible in these cases due to the severity of the disease and keeping in consideration the concepts of impaction and inclusion as described by Rab. The surgical approach as described by Ganz for impingement syndromes in adults was used. A lateral approach with the patients lying on the side was followed by trochanteric osteotomy, anterior capsulotomy and anterior dislocation of the hip. Metaphyseal cuneiform osteotomies were done on all of the hips. Clinical and radiological assessment was done by the Southwick classification. Additional radiological assessment consisted of the evaluation of correction of anatomy on an AP pelvis. The hips were furthermore assessed for AVN by using bone scans. This is a short term follow-up. Of the 6 patients 5 did excellently according to the Southwick result score. One patient had only a fair result due to the damage caused by the impingement prior to the corrective osteotomy. None developed AVN. The management of severe chronic SCFE remains controversial. A single method of management namely pinning in situ can not be used in all degrees of SCFE. Intertrochanteric osteotomies and subtrochanteric osteotomies distort anatomy. It can not be performed for deformities of more than 50 and 70 degrees. Dislocation of the femoral head fascilitates femoral neck osteotomies and can be used safely without the complication of AVN if the Ganz surgical exposure is used

Ganz peri-acetabular osteotomy is commonly used to treat symptomatic hip dysplasia. It aims to increase the load bearing contact area of the hip to reduce the risk of subsequent osteoarthritis. In this study we assess the radiographic and clinical results of the procedure since its introduction to our unit. All patients undergoing Ganz osteotomies at our unit were followed up prospectively. Data collected included patient demographics and pre- and post-operative functional scores (Harris and Non-arthritic hip scores). In addition, acetabular correction was evaluated on pre-and post-operative radiographs (using Centre-Edge angle and Tonnis angle). Complications were also noted. Overall 50 procedures were performed between 2007 and 2013 with median follow-up of 3 years (1 – 7 years). The majority of patients (90%) were female. Average age at time of surgery was 29 years (16–49). There were significant improvements in pre- and post-operative median functional scores (Modified Harris Hip Score = 49 versus 64, p=0.001), Non-arthritic Hip Score = 42 versus 56, p=0.007). Median Centre Edge Angle improved from 16 degrees pre-operatively (range = 7–31 degrees) to 30 degrees post-operatively (18–33) degrees), p<0.0001. Similarly, pre-operative Tonnis angle improved from 18 degrees (9–38) to 7 degrees (2–14), p<0.0001. Five patients developed post-operative complications: 2 superficial wound infection, 1deep infection requiring hip washout and antibiotic treatment and 2 patients subsequently requiring total hip replacements. We have shown that the Ganz peri-acetabular osteotomy can be effective for the treatment of painful hip dysplasia improving both functional and radiographic outcomes. However, patient selection is a key factor

Ganz peri-acetabular osteotomy is commonly used to treat symptomatic hip dysplasia. It aims to increase the load bearing contact area of the hip to reduce the risk of subsequent osteoarthritis. In this study we assess the radiographic and clinical results of the procedure since its introduction to our unit. All patients undergoing Ganz osteotomies at our unit were followed up prospectively. Data collected included patient demographics and pre- and post-operative functional scores (Harris and Non-arthritic hip scores). In addition, acetabular correction was evaluated on pre-and post-operative radiographs (using Centre-Edge angle and Tonnis angle). Complications were also noted. Overall 50 procedures were performed between 2007 and 2013 with median follow-up of 3 years (1–7 years). The majority of patients (90%) were female. Average age at time of surgery was 32 years (17–39). There were significant improvements in pre- and post-operative median functional scores (Modified Harris Hip Score = 52 versus 63, p=0.001), Non-arthritic Hip Score = 49 versus 60, p=0.01). Median Centre Edge Angle improved from 15 degrees pre-operatively (range = 8–19 degrees) to 29 degrees post-operatively (22–36 degrees), p=0.02. Similarly, pre-operative Tonnis angle improved from 19 degrees (16–38) to 7 degrees (2–14), p=0.01. Four patients developed post-operative complications: 1 superficial wound infection, 1deep infection requiring hip washout and antibiotic treatment and 2 patients subsequently requiring total hip replacements. We have shown that the Ganz peri-acetabular osteotomy can be effective for the treatment of painful hip dysplasia improving both functional and radiographic outcomes. However, patient selection is a key factor

Aim: To evaluate the results of hip resurfacing done using the Ganz trochanteric flip osteotomy. Introduction: Long term survivorship of hip resurfacing depends on preservation of blood supply to the head of the femur. The most important artery supplying the head of femur is the deep branch of the medial circum-flex artery. Posterior approaches to the hip can damage the deep branch. The Ganz trochanteric flip osteotomy preserves this branch by sparing the external rotators of the hip. The trochanteric osteotomy is stable as the pull of the gluteus medius on the osteotomy is counteracted by the vastus lateralis. Methods: Over a period of 12 months, the senior author performed hip resurfacing in fifty patients using this approach. The post-operative regime consisted of early mobilisation with touch weight bearing for 6 weeks followed by full weight bearing. The surgical technique and potential pitfalls will be presented. Results and Conclusions: There were 26 males and 24 females with an average age of 57 years (24–71 years). Minimum follow-up period was 12 months. There was one infection, one early failure of osteotomy. In three patients, one or more screws came loose and had to be removed but the osteotomy had healed. Pre and postoperative Oxford hip and modified UCLA activity scores will be presented. There was a definite learning curve with this approach. We find it gives an excellent exposure of the hip with minimal trauma to surrounding tissues. The early results are encouraging. It remains to be seen if this approach results in a better survivorship of hip resurfacing in the long term

Since 1989 the Ganz periacetabular osteotomy has been performed in Christchurch for pain arising from hip dysplasia in selected patients. This review was performed to assess symptoms, function and radiographic appearances at a medium term follow up. The results of 14 peri-acetabular osteotomies performed in 13 patients was evaluated. The mean age of the patients at the time of surgery was 23 years (range 17–44). The mean duration of follow up was 5 years (3 months to 13 years). The follow up examination included clinical evaluation, chart review and radiographic analysis. Of the 13 patients evaluated, improvement in pain was achieved in 12. One required a hip replacement and intermittent discomfort was noted in 3 resulting in restriction in activites. Complications included sciatic nerve palsy (1), leg length discrepancy (2), superficial wound infection (1), scar tenderness (2), numbness in lateral femoral cutaneous nerve distribution (5) and pain from prominent metalware (1). Improvement in femoral head coverage was seen in all patients on follow up x-ray with minimal progression of arthritic changes. Improvement in symptoms ranging from complete relief of pain and participation in high intensity sporting events to intermittent discomfort was achieved. One failure occurred requiring arthroplasty. Significant complications occurred but have largely resolved. The osteotomy was successful in obtaining good relief of symptoms and has prevented the requirement for total hip replacement in this young active group

Background and purpose. At the Ganz periacetabular osteotomy the osteotomized acetabular fragment is reoriented in an adducted, extended and rotated position. Two screws fixate the acetabular fragment and the patients are allowed 30 kg weight bearing immediately after surgery. We were interested in examining the stability of the reoriented acetabulum after the Ganz osteotomy and accordingly the migration of the acetabular fragment was assessed by radiostereometry. Methods. Thirty two dysplastic patients (thirty two hips), twenty seven females and five males were included in the study. Median age was 39 (20–57) years. Radio-stereometric examinations were done at one week, four weeks, 8 weeks and six months. Data are presented as mean with 95% CI. Results. Six months postoperatively, the acetabular fragment had migrated 0.7mm (0.4–1.0mm) medially, and 0.7mm (0.5–0.9 mm) cranially. Mean rotation in valgus direction was 0.5° (−0.1–1.0°). In other directions, migration was below 0.4. There was no statistical difference between migration 8 weeks and 24 weeks postoperative in translation or rotation. Interpretation. This is the first paper dealing with radio-stereometric analysis in Ganz osteotomy. Due to the very limited migration, we find our postoperative partial weight-bearing regime safe

This case series highlights the use of the Ganz approach and surgical dislocation for excision of fibrous dysplasia of the femoral neck, pigmented villonodular synovitis and synovial chrondromatosis of the hip, which has never been described for use with all three tumours together. These are rare benign tumours, which were found incidentally and required excision. We demonstrate that it is possible to obtain excellent exposure of the femoral neck, head and acetabulum allowing easy inspection, exploration and debridement of these three tumours of the hip

Heterotopic ossification is a recognised complication of surgery on the hip joint that can adversely affect the outcome. The aim of this study was to determine the incidence of heterotopic ossification following surgical hip dislocation and debridement for femoro-acetabular impingement using Ganz trochanteric flip osteotomy approach. We also compared the incidence of heterotopic ossification between two subgroups of patients; in the first group, a shaver burr was used to reshape the femoral head and in the second group, an osteotome was used. Methods: We reviewed postoperative radiographs of all patients who underwent surgical hip dislocation and debridement during the period between March 2003 and July 2007. We excluded patients with radiographic follow-up of less than one year. Brooker classification was used to grade heterotopic ossifications. Results: Ninety eight patients (mean age 35 years, range 12–65 years) were included with a mean radiological follow-up of 23 months (range 12–61 months). The overall incidence of heterotopic ossification was 31%. None of the patients developed Brooker grade III or IV heterotopic ossifications. The incidence of heterotopic ossifications in the shaver burr group (n=57) and in the osteotome group (n=41) was 30% and 32%, respectively. Conclusions: Heterotopic ossification of minor grade is a common complication of surgical hip dislocation using trochanteric flip osteotomy approach. The use of a shaver burr did not result in higher rates of heterotopic ossifications despite the formation of large amounts bone debris

Thinning of the femoral neck occurs in 77% of patients undergoing hybrid Birmingham hip resurfacing using a posterior approach (Shimmin 2007). Villar recently reported lower neck thinning rates in uncemented Cormet resurfacings (11.7%) compared with hybrid Birmingham resurfacing (13.4%), both via a posterior approach. We have evaluated implant position and femoral neck thinning in a cohort of 273 uncemented HA coated Cormet 2000 hip resurfacings using ‘B’-series (Titanium/HA coated) cups in 269 patients (mean age 54 years, 39% female) with a mean follow-up of 3 years (range 1–4 years). Mean cup inclination was 45° (30°–63°), mean SSA 138° (120°–178°). No lucent or sclerotic zones have been identified around the stem of the component. Only one femoral neck fracture has occurred (incidence 0.36%). We have identified only one case of femoral neck thinning in our series (0.36%). Whilst Villar has demonstrated a slight reduction in neck thinning rates using the same implants compared to a hybrid fixation Birmingham resurfacing, his neck thinning rates are almost 40 times higher than in our series. Shimmins ‘severe neck thinning (> 10%) rates (27%) are approximately 120 times higher than our series. In addition, we have been unable to confirm the relationship between implant position and neck thinning described by Shimmin in our series using the combined Ganz/uncemented resurfacings compared with Birmingham resurfacings. Implant design and surgical approach have an impact on ‘neck thinning after resurfacing; we should be wary of treating all resurfacing implants and techniques as a uniform cohort

Aims. Femoroacetabular impingement (FAI) describes abnormal bony contact of the proximal femur against the acetabulum. The term was first coined in 1999; however what is often overlooked is that descriptions of the morphology have existed in the literature for centuries. The aim of this paper is to delineate its origins and provide further clarity on FAI to shape future research. Methods. A non-systematic search on PubMed was performed using keywords such as “impingement” or “tilt deformity” to find early anatomical descriptions of FAI. Relevant references from these primary studies were then followed up. Results. Although FAI has existed for almost 5,000 years, the anatomical study by Henle in 1855 was the first to describe it in the literature. The relevance of the deformity was not appreciated at the time but this triggered the development of further anatomical studies. Parallel to this, Poland performed the first surgical correction of FAI in 1898 and subsequently, descriptions of similar procedures followed. In 1965, Murray outlined radiological evidence of idiopathic cam-type deformities and highlighted its significance. This led to a renewed focus on FAI and eventually, Ganz et al released their seminal paper that has become the foundation of our current understanding of FAI. Since then, there has been an exponential rise in published literature but finding a consensus, especially in the diagnosis of FAI, has proven to be difficult. Conclusion. Current research on FAI heavily focuses on new data, but old evidence does exist and studying it could be equally as important in clarifying the aetiology and classification of FAI. Cite this article: Bone Joint Res 2020;9(9):572–577

The Bernese periacetabular osteotomy (PAO) is not indicated for growing hips as it crosses the triradiate cartilage in its posterior branch, and experimental work has shown this can induce substantial deformations, similar to posttraumatic dysplasia, which is observed after pelvis crash injuries in childhood.

Upon examination, all injuries in the 19 cases of posttraumatic dysplasia described in literature plus 16 hips of our personal collection took place before the age of 6, which is striking as pelvic injuries in children increase with age.

Based on this observation, we started to extend the PAO indication to severe dysplasias in children with open growth plate, initially aged 9 years and older. Following the positive results, it was extended further, our youngest patient being 5 years old.

We retrospectively examined radiographic outcomes of 23 hips (20 patients), aged 10.6±1.8 years [range 5.0 – 13.2], operated by us in four centers. Pre- and 3-months postoperative, and the latest FUP radiograph at growth plate closure were measured. We evaluated the acetabular index (AI), lateral center-edge (LCE), ACM-value and compared them with reference values adjusted for age. The age at triradiate cartilage closure was compared with the non-operated side.

The follow-up time was 5.4±3.7 years [0.8 - 12.7]. In 5 hips, growth plate closure was delayed by a few months. All angles significantly normalized after PAO (LCE: 14±8° → 38±11°, AI: 20±8° → 7±4°, ACM: 53±5° → 48±4°), with >80% of them severe pathological pre-PAO, none afterwards. Acetabular molding was normal. Only few complications occurred; one had signs of coxarthosis, one sciatic nerve pain, one interfering osteosynthesis material that was removed, one had an additional valgus osteotomy, and all resolved.

Based on 20 cases with follow-up until complete triradiate cartilage closure, we believe to have sufficient information to extend the PAO indication to growing hips of 9 years and older.

Executing an extended retinacular flap containing the blood supply for the femoral head, reduction osteotomy (FHO) can be performed, increasing the potential of correction of complex hip morphologies. The aim of this study was to analyse the safety of the procedure and report the clinical and radiographic results in skeletally mature patients with a minimum follow up of two years.

Twelve symptomatic patients (12 hips) with a mean age of 17 years underwent FHO using surgical hip dislocation and an extended soft tissue flap. Radiographs and magnetic resonance imaging producing radial cuts (MRI) were obtained before surgery and radiographs after surgery to evaluate articular congruency, cartilage damage and morphologic parameters. Clinical functional evaluation was done using the Non-Arthritic Hip Score (NAHS), the Hip Outcome Score (HOS), and the modified Harris Hip Score (mHHS).

After surgery, at the latest follow-up no symptomatic avascular necrosis was observed and all osteotomies healed without complications. Femoral head size index improved from 120 ± 10% to 100 ± 10% (p<0,05). Femoral head sphericity index improved from 71 ± 10% before surgery to 91 ± 7% after surgery (p<0,05). Femoral head extrusion index improved from 37 ± 17% to 5 ± 6% (p< 0,05). Twenty five percent of patients had an intact Shenton line before surgery. After surgery this percentage was 75% (p<0,05). The NAHS score improved from a mean of 41 ± 18 to 69 ± 9 points after surgery (p< 0,05). The HOS score improve from 56 ± 24 to 83 ± 17 points after surgery (p< 0,05) and the mHHS score improved from 46 ± 15 before surgery to 76 ± 13 points after surgery (p< 0,05).

In this series, femoral head osteotomy could be considered as safe procedure with considerable potential to correct hip deformities and improve patients reported outcome measures (PROMS).

Level of evidence - Level IV, therapeutic study

Keywords - Femoral head osteotomy, Perthes disease, acetabular dysplasia, coxa plana

Total hip arthroplasty for developmental dysplasia of the hip (DDH) remains a difficult and challenging problem. How to reconstruct acetabular deficiencies has become increasingly important. One of the major causes inducing loosening of acetabular reinforcement ring with hook (Ganz ring) is insufficient initial stability. In this study, three-dimensional finite element models of the pelvis with different degrees of bone defect and acetabular components were developed to investigate the effects of the number of screws, screw insert position (Fig. 1), and bone graf quality on the initial stability under the peak load during normal walking. The size of pelvic bone defect, the number of screws and the position of screws were varied, according to clinical experience, to assess the change of initial stability of the Ganz ring. The Ganz ring was placed in the true acetabulum and the acetabular cup was cemented into the Ganz ring with 45 degrees abduction and 15 degrees of screws. The Insert position, nodes on the sacroiliac joint and the pubic symphysis were fixed in all degrees of freedom as the boundary condition. The peak load during normal walking condition was applied to the center of the femoral head (Fig. 2). According to the Crowe classification, as the degree of acetabular dysplasia was increased, the relative micromotion between the Ganz ring and pelvis was also increased. The peak micromotion increased as the stiffness of bone graft decreased. Increasing the numbers of screws, the relative micromotion tended to be reduced and varied the screw insertion position that affects the relative micromotion in the Ganz ring-pelvic interface (Fig. 3). This study showed that increasing the number of inserted screws can reduce the relative micromotion. Both the insert position and graft bone property affect the stability of the Ganz ring while the insert position has a greater impact. The current study is designed to lay the foundation for a biomechanical rationale that will support the choice of treatment

Aims

Avascular femoral head necrosis in the context of gymnastics is a rare but serious complication, appearing similar to Perthes’ disease but occurring later during adolescence. Based on 3D CT animations, we propose repetitive impact between the main supplying vessels on the posterolateral femoral neck and the posterior acetabular wall in hyperextension and external rotation as a possible cause of direct vascular damage, and subsequent femoral head necrosis in three adolescent female gymnasts we are reporting on.

The childhood hip conditions of Developmental Dysplasia, Legg-Calve-Perthes Disease and Slipped Capital Femoral Epiphysis have a wide spectrum of anatomical outcomes following childhood treatment; ranging from morphologies, which result in normal hip function throughout life, to severely deranged morphologies, which result in pain and disability during childhood and adolescence. Some of these outcomes are as a result of well-intentioned interventions that result in catastrophic complications. In 2003, after years of working with impingement complicating periacetabular osteotomies and building on the work of William Harris, Reinhold Ganz published his concepts of ‘cam’ and ‘pincer’ hip impingement, and how these anatomical morphologies resulted in hip arthritis in adulthood. These concepts of impingement were added to his previous published work on hip instability to provide a comprehensive theory describing how hip arthritis develops on the basis of anatomical abnormalities. Surgical techniques have been developed to address each of these morphological pathologies. Ganz's concepts of hip impingement and instability may be applied to severe paediatric hip deformities to direct reconstructive joint preserving surgery to both the femur and the acetabulum. Ganz's surgical approaches have also been refined for use in paediatric hip surgery to allow radical reshaping salvage osteotomies to be performed on the developing femoral head with minimal risk of the devastating consequence of vascular Necrosis