Trapdoor Procedure Research Articles

Modified trapdoor procedure versus complete nail removal for subungual glomus tumor excision at minimum 2 years follow-up

Modified trapdoor procedure versus complete nail removal for subungual glomus tumor excision at minimum 2 years follow-up

The importance of removing osteonecrosis during treatment of femoral head osteonecrosis

Atraumatic femoral head necrosis (aFHN) in adults is estimated to be the leading cause of approximately 10% of all hip prosthesis implantations. Due to the relatively frequent occurrence of aFHN at ayoung age, the possibility of ajoint-preserving intervention should be examined. This includes the classic "core decompression" and modifications based on it. There are different data on the success rates of this method. Reasons for treatment failure could include a lack of clearance of the necrosis zone. The clearance of the necrosis zone is taken into account by alternative surgical procedures for the treatment of aFHN. These are the "trap-door procedure", the "light-bulb procedure" and "advanced core decompression". The current state of knowledge on these procedures is reviewed in this keynote article. It is shown that the extensive excision of femoral head necrosis is of particular importance. None of the procedures mentioned can currently be recommended in preference over the others.

Individual treatment strategy for single urethrocutaneous fistula after hypospadias repair: a retrospective cohort study.

BackgroundUrethrocutaneous fistula (UCF) remains the most common complication after hypospadias repair, and the recurrence rate of UCF is still high if the surgical techniques is not chosen properly, which called for better approaches to this problem. UCF presents different clinical characteristics due to their different locations and sizes, therefore we retrospectively analyzed the effects of different surgical techniques on single UCF after hypospadias repair in order to reduce the recurrence rates of UCF.MethodsA total of 602 patients diagnosed with UCF after hypospadias repair from January 2014 to December 2021 were enrolled. Baseline clinical characteristics such as age of patients, UCF location, size, surgical techniques were recorded. Patients were followed up in the outpatient clinic. The recurrence of UCF was defined as outcomes. Patients were divided according to the location of the UCF into a coronal UCF group and a non-coronal UCF group, which was then further classified according to the diameter of the UCF. The surgical technique and the recurrence rate of different types of UCF were analyzed and summarized.ResultsA total of 425 patients satisfied the inclusion criteria and 71 patients (16.7%) had recurrent UCF. Five surgical techniques were used to repair the UCF, namely tubularized incised plate (TIP) urethroplasty, Mathieu urethroplasty, double ligation, simple classical closure and trap-door procedure. The recurrence rate was 24.1%, 14.3%, 15.1%, 16.7%, and 22.2%, respectively. TIP or Mathieu urethroplasty is recommended for patients with coronal UCF with glans dehiscence or patients with coronal UCF diameter ≥4 mm without glans dehiscence. In patients with coronal UCF without glans dehiscence, double ligation is recommended for small UCF with diameter <2 mm, and simple classical closure is recommended for UCF with diameter 2–<4 mm. In patients with non-coronal UCF, double ligation is recommended for UCF with diameter <3 mm, and simple classical closure is recommended for UCF with diameter ≥3 mm.ConclusionsSingle UCF can be classified according to the location and size of the UCF. Different types of UCF should be treated with more appropriate individualized strategies, which can effectively reduce the recurrence rate of UCF.

Direct femoral head approach without surgical dislocation for femoral head chondroblastoma: a report of two cases

BackgroundChondroblastomas are rare, benign, locally aggressive lesions that appear in the epiphysis. Surgery for femoral head chondroblastoma (FHCB) is difficult. Conventional treatment with curettage via a drilled tunnel along the femoral neck can damage the growth plate and is associated with high local recurrence rates. The trapdoor procedure, which directly facilitates lesion access from the femoral head articular surface, can reduce local recurrence and avoid growth plate damage, although it requires surgical dislocation. Little is known about the long-term results of this direct articular surface approach, and there are no case reports on trapdoor procedures without dislocation.Case presentationWe report two cases (patients aged 12 and 15 years) of FHCB presented with coxalgia treated using the trapdoor procedure without surgical dislocation. Both surgeries were performed with patients in the semi-lateral position. The hip joint was exposed via an anterior approach, and a capsulotomy was performed at the superior rim of the acetabulum, followed by the external rotation of the hip joint. With a fine osteotome, a rectangular flap (trapdoor) was opened on the cartilage surface in the lateral non-weight-bearing area, and curettage of the lesion followed by bone and/or bone substitute grafting was performed. Subsequently, the trapdoor was replaced in its original position. There has been no local recurrence or femoral head aseptic necrosis after more than 6 and 12 years for patients 1 and 2, respectively. Both patients had musculoskeletal tumor society scores of 100% at follow-up and are enjoying a normal active life.ConclusionsThis direct femoral head approach without dislocation may be a simple treatment alternative for FHCB.

A new modification of the Trapdoor Procedure without surgical hip dislocation in the management of patients with osteonecrosis of the femoral head: A retrospective case series.

The aim of this paper was to investigate the mid-term results of a modified Trapdoor procedure that can allow grafting of the femoral head without surgical hip dislocation in the management of patients with osteonecrosis of the femoral head. 16 hips of 12 patients (7 female, 5 male; mean age = 38.5 ± 10.7) surgically treated by the new modification of Trapdoor procedure were retrospectively reviewed and included in the study. Based on the Association Research Circulation Osseous (ARCO) classification system, seven hips (43.7%) were stage 2, and nine hips (56.3%) were stage 3. The mean follow-up was 48.4 ± 25.7 months (range = 12-107). All the patients were evaluated postoperatively at the 6th week, 3rd month, 6th month, 1st year, and annually thereafter until their final follow-up. Clinical assessment was performed using the Harris Hip scoring (HHS) system, Non-Arthritic Hip score (NAHS) and Visual analogue pain scale (VAS). At the final follow-up, degenerative changes were examined according to the Kellgren-Lawrence scale. ThemeanHHS increased from53.43 ± 9.0 (range = 36-67) preoperatively to 83.81 ± 6.1 (range = 72-95) at the final follow-up (P < 0,001). Themean NAHS increased from 51.5 ± 8.2 (range = 36.25-61.25) preoperatively to 86 ± 3.2 (range = 81.5-90) (P < 0,001) at the final follow-up. The mean preoperative VAS decreased from 7.85 ± 0.9 (range = 6.45-9.5) to 3.05 ± 0.9 (range = 1.6-5.2) (P < 0,001) at the final follow-up. 13 hips demonstrated 80 and higher scores according toHHS. In the remaining three hips (ARCOstage 3), the mean postoperative HHS, NAHS, and VAS scores were 76, 82, and 3,2 respectively. According to Kellgren-Lawrence scale, three hips (18,75%) were determined as grade 0, 10 hips (62.5%) as grade 1, and 3 hips (18.75%) as grade 2. The Modified Trapdoor procedure without surgical hip dislocation seems to be a suitable technique with favorable clinical outcomes for the treatment of ARCO stage 2 and stage 3 osteonecrosis of the femoral head. Level IV, Therapeutic Study.

Modified trapdoor procedures using autogenous tricortical iliac graft without preserving the broken cartilage for treatment of osteonecrosis of the femoral head: a prospective cohort study with historical controls

BackgroundThe aim of the present study was to investigate clinical and radiological outcomes of autologous tricortical iliac grafting performed through a window created at the femoral head without suturing the opened articular cartilage for the treatment of osteonecrosis of the femoral head (ONFH), called modified trapdoor procedures.Materials and methodsA total of 59 consecutive patients (67 hips; 36 males and 23 females) with ONFH were included in this study, which was conducted from April 2009 to March 2012. Patients’ age ranged from 27 to 46 years old, with a mean age of 36.3 years. Harris hip scores (HHS) were used to evaluate hip function pre- and postoperatively. Anteroposterior and frog-position X-rays and magnetic resonance imaging (MRI) were conducted to assess lesion location, size, and ARCO stage. Clinical failure was defined as score < 80 points or treatment by total hip arthroplasty (THA). Radiographic failure was defined as a > 3 mm of collapse in the hip. This group was retrospectively matched according to the ARCO stage, extent, location, etiology of the lesion, average age, gender, and preoperative Harris hip score to a group of 59 patients (67 hips) who underwent the “light bulb” approach between March 2007 and April 2009.ResultsMean follow-up was 91.2 ± 13.6 months (range, 75–115 months). Mean HHS was 91.3 ± 4.5, compared with 83.1 ± 4.5 in the “light bulb” cohort at the 6-year follow-up examination (P < 0.001). At the 6-year follow-up, for modified trapdoor procedures, five hips (8.5%) were classified as clinical failure, and three hips underwent total hip arthroplasty; seven hips were classified as (10.4%) radiographic failure. The clinical and radiographic failure of the hips treated with the modified trapdoor procedure was significantly lower compared to the hips treated with the “light bulb” procedure (P < 0.05). Survival of the joint was not significantly related to the location of the femoral head lesion between two groups; however, better clinical and radiographic results were observed in modified trapdoor procedures with size C and the ARCO stage III.ConclusionThe present study demonstrated superior midterm clinical results in ONFH with the use of autologous tricortical iliac block graft through a femoral head window, without suturing the opened articular cartilage. The femoral head-preserving procedure was superior compared to the “light bulb” procedure treatment in patients with postcollapse osteonecrosis and large lesion.

Femoral osteotomies for the treatment of avascular necrosis of the femoral head.

Unloading of the area of necrosis out of the weight-bearing region by shifting healthy bone in the main weight-bearing area, which may delay the progression of the necrosis and enable healing. Circumscribed osteonecrosis of the femoral head without advanced degenerative signs (Tönnis grade ≤ 1) in the relatively young patient (age < 50years). Radiographic joint degeneration (> Tönnis grade1); extensive avascular necrosis (Kerboul angle > 240°); advanced lesions (≥ Association Research Circulation Osseous [ARCO] classification3b). By performing asurgical hip dislocation, full access to the hip joint is gained. Afemoral varus osteotomy is used to turn the necrotic lesion of the femoral head out of the central weight-bearing area and more medially. Osteosynthesis is performed with an angular stable screw or ablade plate. Via atrapdoor procedure, direct debridement and autologous bone grafting from the trochanter major is possible. The cartilage flap is preserved whenever possible or supplanted by an autologous matrix-induced chondrogenesis (AMIC). Apassive motion device is installed during hospital stay beginning immediately after surgery to prevent capsular adhesions. After surgery, patients are mobilized with partial weight-bearing of 15 kg with the use of crutches for at least 8 weeks. Forced abduction and adduction as well as flexion of more than 90° are restricted to protect the trochanteric osteotomy. After radiographic confirmation of healing at the 8‑week follow-up, stepwise return to full weight-bearing is allowed and abductor training is initiated. Nine patients (10hips) with osteonecrosis of the femoral head were treated with surgical hip dislocation and varus osteotomy. Six hips were treated with autologous bone grafting, four hips with antegrade drilling. Chondral lesions were sutured in four cases, whereas two cases needed an AMIC treatment. The mean age at operation was 29 ± 9years (20-49), and the mean follow-up time for all patients was 3 ± 2years (1-7). Conversion to atotal hip prosthesis was required for one hip with progressing arthrosis. The other nine hips showed no progression of necrosis and an improved clinical outcome. Complications were pseudarthrosis of the femoral osteotomy and pseudarthrosis of the greater trochanter.

Modified trapdoor procedures by surgical dislocation approach to treat chondroblastoma of the femoral head.

The aim of this study was to evaluate the efficacy of the surgical dislocation approach and modified trapdoor procedure for the treatment of chondroblastoma of the femoral head. A total of 17 patients (ten boys, seven girls; mean age 16.4 years (11 to 26)) diagnosed with chondroblastoma of the femoral head who underwent surgical dislocation of the hip joint, modified trapdoor procedure, curettage, and bone grafting were enrolled in this study and were followed-up for a mean of 35.9 months (12 to 76). Healing and any local recurrence were assessed via clinical and radiological tests. Functional outcome was evaluated using the Musculoskeletal Tumour Society scoring system (MSTS). Patterns of bone destruction were evaluated using the Lodwick classification. Secondary osteoarthritis was classified via radiological analysis following the Kellgren-Lawrence grading system. Steinberg classification was used to evaluate osteonecrosis of the femoral head. The epiphyseal plate was open, closing, and closed in five, five, and seven patients, respectively. In total, eight, six, and three patients were classified as having Lodwick classification IA, IB, and IC, respectively. Allogeneic and autogenous bone grafting was used in 13 and four patients, respectively. All patients had good bone healing and no local recurrence was observed. One patient developed osteonecrosis of the femoral head (Steinberg IA) and one developed secondary osteoarthritis of the hip joint (Kellgren-Lawrence Grade II). The mean postoperative MSTS functional score was 27.7 (24 to 30). Surgical dislocation and modified trapdoor procedures are safe and effective techniques for treating chondroblastoma in the femoral head. Cite this article: Bone Joint J 2019;101-B:732-738.

Femoral neck trapdoor procedure and allograft for the chondroblastoma of the femoral head

The chondroblastoma is a kind of benign bone tumor which mainly arises from epiphyseal plate, including proximal parts of humerus, tibia and the proximal part of the femur. The reported incidence of femoral head chondroblastoma is rare, accounting for approximately 1–2% of bone tumors. The main treatments reported include acetabular osteotomies, osteochondral grafts, and vascularized fibular grafts. We present a case of femoral head chondroblastoma treated with a femoral neck trapdoor procedure and allograft. The hip function of this male patient recovered well, with no recurrence or complications found at 16 months follow-up. This procedure may be a sufficient and safe approach for the chondroblastoma of the femoral head.

CORR Insights®: what are the results using the modified trapdoor procedure to treat chondroblastoma of the femoral head?

This CORR Insights® is a commentary on the article “What Are the Results Using the Modified Trapdoor Procedure to Treat Chondroblastoma of the Femoral Head?” by Xu and colleagues available at: DOI: 10.1007/s11999-014-3771-y. The author certifies that he, or any member of his immediate family, has no funding or commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research ® editors and board members are on file with the publication and can be viewed on request. The opinions expressed are those of the writers, and do not reflect the opinion or policy of CORR ® or the Association of Bone and Joint Surgeons®. This CORR Insights® comment refers to the article available at DOI: 10.1007/s11999-014-3771-y.

What are the results using the modified trapdoor procedure to treat chondroblastoma of the femoral head?

Treatment of chondroblastoma in the femoral head is challenging owing to the particular location and its aggressive nature. There is little published information to guide the surgeon regarding the appropriate approach to treating a chondroblastoma in this location. We developed a modified trapdoor procedure to address this issue. The primary modification is that the window surface of the femoral head is covered by the ligamentum teres rather than cartilage as in the traditional procedure. We assessed (1) the clinical presentation of chondroblastoma of the femoral head and treatment results with the modified trapdoor procedure in terms of (2) the frequency of local recurrence, (3) complications, and (4) functional outcomes using the Musculoskeletal Tumor Society (MSTS) score. Between 1999 and 2010, we treated 14 patients for chondroblastoma of the femoral head. All patients received the modified trapdoor procedure. Of those, 13 were available for followup at a minimum of 36months (mean, 66months; range, 36-117months) and one patient was lost to followup. There were nine males and four females, with a mean age of 18years (range, 9-29years). Clinical features were ascertained by chart and radiographic review, and recurrence, complications, and functional outcomes (MSTS score) were recorded from chart review. Patterns of bone destruction were evaluated using the Lodwick classification, which ranges from IA (geographic appearance with sclerotic rim) to III (permeative appearance). The symptoms at diagnosis were pain in nine patients and discomfort in four. The mean duration of symptom was 11months (range, 1-36months). The physis was open in two patients, closing in one, and closed in 10. The patterns of bone destruction were evaluated as Lodwick Class IA in six patients, Lodwick Class IB in five, and Lodwick Class IC in two. At latest followup, no local recurrence was observed. Two patients had postoperative complications. One had avascular necrosis of the femoral head and was treated with prosthesis replacement. The other had asymptomatic heterotopic ossification in the surgical field. The mean MSTS score was 29.6 (range, 28-30). Based on this small series, we believe our modified trapdoor procedure is a safe, effective means of treating a chondroblastoma in the femoral head, but additional clinical evaluation with more patients is necessary to confirm our findings. Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Micro‐CT‐based bone ceramic scaffolding and its performance after seeding with mesenchymal stem cells for repair of load‐bearing bone defect in canine femoral head

Osteonecrosis of the femoral head is a debilitating and painful orthopedic condition characterized by joint collapse. Salvage of the femoral head is highly desirable to preserve the contour and mechanical properties and prevent joint collapse. This study aimed to develop a new tissue-engineering approach for treatment of large bone defect in femoral head, that is, after osteonecrosis. The biphasic calcium phosphate (BCP) ceramic scaffolds were fabricated by a 3D gel-lamination technique based on micro-computed tomography (micro-CT) images of the cancellous bone microarchitecture of femoral heads. After seeding with autologous bone marrow-derived mesenchymal stem cells (BMSCs) in vitro, the cell-scaffold composite was implanted into a bone defect surgically induced in canine femoral head via trapdoor procedure, which was a common procedure for treatment of osteonecrosis. A total of 24 adult dogs were randomly divided into three groups (n = 8 each) for implantation of the BCP scaffold with or without with BMSCs, and also the autologous bone chips for comparisons. All animals were sacrificed at 30 weeks postoperatively and processed for radiological and histological evaluations. The contour of the femoral head was well preserved with implantation of BCP scaffolds with or without BMSCs, whereas joint collapse was found after treatment with autologous bone chips. The osteointegration and new bone formation was significantly greater with BCP scaffold implantation with than without BMSC seeding and showed greater strength and compressive modulus in the repair site. Micro-CT-based bone ceramic scaffolds seeding with BMSC might be a promising way to repair bone defects in the femoral head.

Surgical Dislocation in the Management of Pediatric and Adolescent Hip Deformity

The surgical dislocation approach is useful in assessing and treating proximal femoral hip deformities commonly due to pediatric conditions. We sought to demonstrate the efficacy and problems associated with this technique. Diagnoses included slipped capital femoral epiphysis, Perthes disease, developmental dysplasia of the hip, osteonecrosis, and exostoses. Through this approach, femoral head-neck osteoplasty (22), intertrochanteric osteotomy (eight), femoral head-neck osteoplasty plus intertrochanteric osteotomy (15), femoral neck osteotomy (five), open reduction and internal fixation of an acute slipped capital femoral epiphysis with callus resection (five), open reduction and internal fixation of an acetabular fracture (one), trapdoor procedure (one), and acetabular rim osteoplasty (one) were performed. The average patient age was 16 years. The minimum followup was 12 months (average, 41.6 months; range, 12-73 months). Patients with Perthes disease and SCFE had preoperative and postoperative WOMAC scores of 9.6 and 5.1, and 7.9 and 3.5 respectively. In patients with unstable SCFEs, the average postoperative WOMAC score was 1.2. Seven patients underwent THAs and two patients underwent hip fusion. Complications in the 58 procedures included four cases of osteonecrosis: three after femoral neck osteotomy and one after intertrochanteric osteotomy. The surgical dislocation technique can be utilized to effectively treat these deformities and improve short-term symptoms. Although the technique is demanding, we believe surgical dislocation offers sufficient advantages in assessing and treating these complex deformities that it justifies judicious application.

Comparison of Bony Healing and Cartilage Degeneration Following Strut Grafting and Trapdoor Procedures in an Ovine Model

This experimental study compared bony healing and cartilage degeneration following strut grafting and trapdoor procedures for osteonecrosis of the femoral head in an ovine model. Osteonecrosis and a bony defect were created surgically in 16 hips of 8 Merino sheep, and the index grafting procedures were performed in a second session. Three months after surgery, the hips treated by strut grafting yielded better articular cartilage protection and bony healing compared to the osteonecrosis groups. The trapdoor group yielded better bony healing compared to the rest of the groups, but the grafts and the osteochondral flaps failed to unite with the host bone. These findings indicate elevating the osteochondral flap during the trapdoor procedure injures the cartilage and may cause degeneration.

A trapdoor procedure for chondroblastoma of the femoral head: a case report

Chondroblastoma located in the femoral head is one of the locations accounting for frequent recurrence. One of the reasons for this is the difficulty in obtaining appropriate surgical access to it for adequate removal of tumors. The authors present and illustrate a trapdoor procedure for the surgical treatment of chodroblastoma in the epiphysis of the femoral head. The surgical approach was made over the great trochanter and a trochanteric osteotomy was performed. The capsulotomy was made anteriorly and posteriorly, and the hip was dislocated anteriorly. Using a scalpel and an osteotome, the edges of a trapdoor segment were sharply dissected and the rectangular segment was lifted back to reveal an underlying subchondral tumor. The tumor tissue was thoroughly curetted and autologous cancellous bone was grafted. The trapdoor was replaced without any additional fixation, and the femoral head was reduced. The patient recovered good hip function without pain, and showed no recurrence of chondroblastoma at 5 years after surgery. The trapdoor procedure enabled sufficient access to complete curettage and autologous cancellous bone grafting for the chondroblastoma of the femoral head. This procedure proved to be a useful surgical approach for the treatment of chodroblastoma in the epiphysis of the femoral head in this case.

Impacted Bone and Calcium Phosphate Cement for Repair of Femoral Head Defects

Bone impaction grafting has been advocated for reconstruction of femoral head osteonecrosis. However, bone grafts do not prevent the progression of collapse and subsequent disabling osteoarthritis in late-stage osteonecrosis. We hypothesized reconstruction of large subchondral defects with a mix of impacted morsellized cancellous bone grafts and calcium phosphate cement would afford mechanical stability allowing remodeling into new bone without femoral head collapse. In a pilot study we created a critically sized subchondral defect model in 15 goats following the trapdoor procedure. Defects were left empty (n = 3), filled with morsellized cancellous bone grafts (n = 6), or filled with a mixture of morsellized cancellous bone and calcium phosphate cement (n = 6). No defects collapsed by sacrifice at 12 weeks. Defects filled with morsellized cancellous bone showed complete incorporation and remodeling to a normal trabecular structure. In the morsellized cancellous bone/calcium phosphate cement group, most of the calcium phosphate cement was resorbed in 12 weeks and the mixture was largely replaced by fibrous or fatty marrow. Although the specific mixture did not confirm our hypothesis, we suspect a slower resorbing calcium phosphate cement remains a promising material to mix with morsellized cancellous bone to treat late stages of femoral head osteonecrosis.

Repairing Defect and Preventing Collapse of Canine Femoral Head Using Titanium Implant Enhanced by Autogenous Bone Graft and rhBMP-2

There is a direct relationship between mechanical stress and the progressive collapse of the necrotic region in osteonecrosis of the femoral head. The titanium implant combined with autogenous bone graft and recombinant human bone morphogenetic protein (rhBMP)-2 to repair the defect and prevent collapse of the femoral head was investigated. The femoral head defects were made by the trapdoor procedure and then the defects were filled, respectively, with the titanium implant combined with autogenous bone graft and rhBMP-2, with autogenous bone graft and rhBMP-2, and with autogenous bone graft alone. Roentgenographic and histological examinations were performed at various times postoperatively. The defects were repaired completely and the titanium implant was integrated with the surrounding bone tissues. The defects healed faster than did without rhBMP-2. No trapdoor cartilage collapsed and joint space narrowed. The titanium implant combined with autogenous bone graft and rhBMP-2 can enhance the repairing procedure and prevent the collapse of the femoral head.

Strut-Autografting with and without Osteogenic Protein-1

Osteonecrosis of the femoral head frequently leads to collapse of the articular cartilage and to disabling osteoarthritis, which ultimately may necessitate joint arthroplasty. One treatment method that has had moderate success is the so-called trapdoor approach, which involves excavation of diseased (necrotic) bone followed by bone-grafting. Augmentation of this procedure with various growth and differentiation factors may improve the outcome. We developed a canine model that mimics the clinical situation with trapdoor bone-grafting. The objective of this study was to evaluate the effect of the addition of osteogenic protein-1 on healing following the trapdoor procedure with strut-autografting. Thirty-four skeletally mature dogs were used in the experiment. After capsulotomy, a trapdoor was created in the anterolateral surface of the femoral head and a 2-cm-diameter subchondral area of bone was removed. In the phase-I experiments, seven dogs had no treatment of the defect (Group I) and nine dogs were treated with strut-grafting (Group II). In phase II, the procedure was modified by collapsing the trapdoor into the created defect intraoperatively in eighteen dogs, which were divided into three equal groups: six untreated defects were left collapsed (Group III), six were treated with bone graft (Group IV), and six were treated with bone graft augmented with osteogenic protein-1 (Group V). Three of the seven femoral heads in Group I (untreated defect) and one of the nine heads in Group II (grafting without collapsing of the trapdoor) had evidence of cartilage collapse. Inspection of sagittal slices and radiographs revealed an unfilled residual defect in all Group-I heads, whereas all Group-II heads were well healed. The mean normalized stiffness value was significantly larger in Group II than it was in Group I. On visual inspection, depression was noted in all of the femoral heads in Group III (untreated defect; trapdoor left collapsed). In both Group IV and Group V (grafting without and with osteogenic protein-1), the trapdoor cartilage appeared to be essentially normal. Groups IV and V had more radiographic healing than did Group III. The defects in Group V (grafting with osteogenic protein-1) healed faster radiographically than did those in Group IV (grafting without osteogenic protein-1). Moderate-to-excellent healing was seen both radiographically and biomechanically by four months in the groups treated with grafting, with and without osteogenic protein-1, whereas untreated defects did not heal. Symptomatic osteonecrosis of the femoral head is a clinical challenge. The animal model in the current study is a useful tool for the evaluation of methods to treat osteonecrosis of the femoral head. Studies investigating additional time-periods between implantation of osteogenic protein-1 and assessment of results as well as different doses of osteogenic protein-1 are warranted.

Osteonecrosis of the Femoral Head After Traumatic Hip Dislocation in the Adult

Osteonecrosis of the femoral head is most commonly classified according to the system of Ficat and Arlet, and the choice of treatment is based directly on the corresponding stage. Therefore it is important to accurately determine the stage of the disease because it has important bearings on the patient's clinical course. Patients with Stage I lesions (preradiologic stage of the disease) usually can be treated with pulsed electromagnetic fields with or without a core decompression, bone grafting and decompression, and rotational intertrochanteric osteotomy. These procedures are equally applicable for patients with Stage II lesions but frequently additional measures such as vascularized fibular grafting and intertrochanteric osteotomy may be necessary. Patients with Stages III and IV lesions also may be treated in a similar way, especially if one wishes to avoid total hip arthroplasty, especially in younger patients. The trapdoor procedure with autogenous cancellous bone and cortical bone grafting can be successful in Stage III osteonecrosis of the hip in patients with small- to medium-sized lesions. When core decompression is used to treat patients with Stage III lesions, an 89% satisfactory outcome can be expected providing that the lesion is small and central, and does not have head depression. Many times the number and variety of procedures tend to reflect the relatively poor results and the desire to avoid total hip arthroplasty. Arthrodesis continues to be an excellent and predictable treatment option and may be indicated when unilateral trauma is the etiology.

The trapdoor procedure using autogenous cortical and cancellous bone grafts for osteonecrosis of the femoral head

We have reviewed the results of 30 operations performed on 23 patients with Ficat stage-III or stage-IV osteonecrosis of the femoral head in which autogenous cortical and cancellous bone grafting had been performed through a so-called trapdoor made in the femoral head. At a mean of 56 months (30 to 60) after operation 20 of 24 stage-III hips (83%) had a good or excellent result as determined by the Harris hip-scoring system. Two of six stage-IV hips (33%) had good or excellent results. Eighteen of 21 hips (86%) with a combined necrotic angle of 200° had good or excellent clinical results compared with only four of nine hips (44%) with a combined necrotic angle of more than 200°. Six of the eight hips which had fair or poor results were in patients who had received corticosteroids; five of these six hips had lesions with a combined necrotic angle of greater than 200° or were in a late stage (stage IV). There were no perioperative complications. Our results suggest that the trapdoor procedure with autogenous cancellous and cortical bone grafting can be successful in Ficat and Arlet stage-III osteonecrosis of the hip in patients with small- to medium-sized lesions.