Does total hip arthroplasty with high hip centre in dysplasia compromise acetabular bone stock?

Background: The placement of uncemented acetabular components during total hip arthroplasty (THA) in Crowe II and Crowe III dysplasia can be at the anatomic or high hip centre position. Purposes: Using computerised tomography data, we simulated acetabular cup placement at the anatomic hip centre and the high hip centre positions to assess whether there is a difference between the 2 in terms of bone loss from acetabular reaming and in acetabular coverage by host bone. Methods: The study population included a consecutive cohort of 19 patients (22 hips) with Crowe II or III dysplasia. 3-dimensional models of the pelvis were created for each patient and digital templating was used to determine the anatomic and high hip centre positions. The coordinates of the digitally templated cup positions were fed into an image processing software to estimate the amount of bone reamed, the cup coverage by host bone and the elevation from tear drop. Results: The mean volume of bone reamed was greater in the high hip centre position as compared to the anatomic position (27.3 ± 11. 4 cm3 vs. 19.4 ± 12.2 cm3, p < 0.0001). The coverage of the acetabular cup by host bone was greater in the high hip centre position (87.3 ± 5.9% vs. 68.3 ± 10%). The mean elevation in the high hip centre group was 13 mm with 3 hips having a breach of the medial wall. Conclusions: In Crowe II and III dysplasia, placement of acetabular cups at the anatomic hip centre better preserves bone stock as compared to high hip centre placement and should be preferred in young patients requiring THA.

Custom-Made 3D-Printed Implants as Novel Approach to Reconstructive Surgery after Oncologic Resection in Pediatric Patients

Recently, custom-made 3D-printed prostheses have been introduced for limb salvage surgery in adult patients, but their use has not been described in pediatric patients. A series of 11 pediatric patients (mean age 10.8 years; range 2–13) with skeletal tumors treated with custom-made implants for the reconstruction of bony defects is described. Patients were followed up every 3 months. Functional results were evaluated by the Musculoskeletal Tumor Society Score (MSTS) for upper and lower limbs. The mean follow-up was 25.7 months (range 14–44). Three patients died after a mean of 19.3 months postoperatively—two because of disease progression and the other from a previous malignancy. Three patients experienced complications related to soft tissues. One patient required device removal, debridement, and antibiotic pearls for postoperative infection. Partial osseointegration between grafts and host bone was observed within a mean of 4 months. At the final follow-up, mean MSTS score was 75%. 3D prostheses may yield biological advantages due to possible integration with the host bone and also through the use of vascularized flaps. Further research is warranted.

Saw transection of retained compression screws with damaged heads instead of removal in revision first metatarsal osteotomy: a technique tip

Distal first metatarsal osteotomy is performed to correct hallux valgus. The surgery is being performed throughout the UK in increasing numbers. The osteotomies used are commonly fixed with one or two variable pitch compression screws. Recurrence of the deformity or inadequate correction in the primary surgery may require revision osteotomy which necessitates removal of previous screws. Revision rates for scarf osteotomy have been reported at 5%. Removal of screws can be challenging as they are often buried in bone and/or the screw heads can get damaged even despite meticulous preparation. Various techniques for removal of damaged screws are described, which require additional equipment and may result in significant loss of the host bone. We describe another technique where a standard Stryker TPS sagittal saw and saw blade (Kalamazoo, USA) are used to cut through the shaft of the compression screws in line with the planned revision osteotomy. We have successfully performed this on two occasions with good results, and describe our experience of using this technique which eliminates the need for complex over drilling procedures often required for removing stripped and retained screws

Controlled fracture of the medial wall versus structural autograft with bulk femoral head to increase cup coverage by host bone for total hip arthroplasty in osteoarthritis secondary to developmental dysplasia of the hip: a retrospective cohort study

Background Many methods have been proposed to increase cup coverage by host bone during primary total hip arthroplasty (THA) in hip osteoarthritis secondary to developmental dysplasia of the hip (DDH). However, there was no study comparing the results of controlled fracture of the medial wall with a structural autograft with a bulk femoral head. Methods Sixty-seven hips classified as Crowe II/III were retrospectively included in this cohort study, which consisted of 33 controlled fractures (group A) and 34 structural autografts (group B). The Harris Hip Scores (HHS) were recorded. The radiological assessments were analyzed. Also, complications are assessed. The paired-sample t test was used for data analysis before and after the operation, while the independent sample T test was used for the comparison between the two groups. The Pearson chi-square test or the Fisher exact test was used to analyze the qualitative comparative parameters. Kaplan-Meier was utilized in the analysis of survivorship with the end points as a revision for any component. Results All patients were reconstructed acetabulum at the anatomical location. HHS increased greatly for both groups (p = 0.18). No statistic difference was observed for the two groups in postoperative leg-length discrepancy (0.51 ± 0.29 cm for group A and 0.46 ± 0.39 cm for group B, p = 0.64 ), postoperative height of the hip center (2.25 ± 0.42 cm for group A and 2.09 ± 0.31 cm for group B, p = 0.13), and inclination of the cup (39 ± 4° for group A and 38 ± 3° for group B, p = 0.65 ). The rate of cup coverage for group B (94 ± 2%) was better than for group A (91 ± 5%), (p = .009). The rate of cup protrusio was 48 ± 4% for group A. For both groups, no statistical difference was observed in the cup diameter (p > .05), while group A showed less operation time than group B (p < .001). No complications were observed at the latest follow-up. Conclusion Controlled fracture of the medial wall to increase cup coverage by host bone at the anatomical location can act as an alternative technique for DDH Crowe II/III with the advantage of shorter operation time and less technically demanding.

Controlled fracture of medial wall versus structural autograft with bulk femoral head to increase cup coverage by host bone for total hip arthroplasty in osteoarthritis secondary to developmental dysplasia of hip: a retrospective cohort study

Background: Many methods have been proposed to increase cup coverage by host bone during primary total hip arthroplasty (THA) in hip osteoarthritis secondary to developmental dysplasia of hip (DDH). However, there was no study comparing results of controlled fracture of medial wall with structural autograft with bulk femoral head. Methods: 67 hips classified as Crowe II/III were retrospectively included in this cohort study, which consisted of 33 controlled fracture (group A) and 34 structural autograft (group B). The Harris Hip Scores (HHS) was recorded. The radiological assessments were analyzed. Also, complications are assessed. The paired sample t test was used for data analysis before and after operation, while independent sample T test was used for the comparison between the two groups. The Pearson chi-square test or Fisher exact test was used to analyze the qualitative comparative parameters. Kaplan-Meier was utilized in the analysis of survivorship with the end points as a revision for any component.Results: All patients were reconstructed acetabulum at anatomical location. HHS increased greatly for both groups (P=0.18). No statistic difference was observed for two groups in postoperative leg-length discrepancy ((0.51±0.29) cm for group A and (0.46±0.39) cm for group B, P=0.64 ), postoperative height of hip center ((2.25±0.42) cm for group A and (2.09±0.31) cm for group B, P=0.13), inclination of cup ((39±4)°for group A and (38±3)°for group B, P=0.65 ). The rate of cup coverage for group B ((94±2)% ) was better than group A ((91±5)%), ( P=.009). Rate of cup protrusio was (48±4)% for group A. For both groups, No statistic difference was observed in cup diameter (P＞.05), while group A showed less operation time than group B (P＜.001). No complications were observed at the latest follow-up. Conclusion: Controlled fracture of medial wall to increase cup coverage by host bone at anatomical location can act as an alternative technique for DDH Crowe II/III with advantage of shorter operation time and less technically demanding.

Controlled Fracture of Medial Wall Versus Structural Autograft With Bulk Femoral Head to Increase Cup Coverage by Host Bone for Total Hip Arthroplasty in Osteoarthritis Secondary to Developmental Dysplasia of Hip: a Retrospective Cohort Study

Background: Many methods have been proposed to increase cup coverage by host bone during primary total hip arthroplasty (THA) in hip osteoarthritis secondary to developmental dysplasia of hip (DDH). However, there was no study comparing results of controlled fracture of medial wall with structural autograft with bulk femoral head. Methods: 67 hips classified as Crowe II/III were retrospectively included in this cohort study, which consisted of 33 controlled fracture (group A) and 34 structural autograft (group B). The Harris Hip Scores (HHS) was recorded. The radiological assessments were analyzed. Also, complications are assessed. The paired sample t test was used for data analysis before and after operation, while independent sample T test was used for the comparison between the two groups.Results: All patients were reconstructed acetabulum at anatomical location. HHS increased greatly for both groups (P=0.18). No statistic difference was observed for two groups in postoperative leg-length discrepancy ((0.51±0.29) cm for group A and (0.46±0.39) cm for group B, P=0.64 ), postoperative height of hip center ((2.25±0.42) cm for group A and (2.09±0.31) cm for group B, P=0.13), inclination of cup ((39±4)°for group A and (38±3)°for group B, P=0.65 ). The rate of cup coverage for group B ((94±2)% ) was better than group A ((91±5)%), ( P=.009). Rate of cup protrusio was (48±4)% for group A. For both two groups, no complications were observed at the latest follow-up. Conclusion: Controlled fracture of medial wall to increase cup coverage by host bone at anatomical location can act as an alternative technique for DDH Crowe II/III with advantage of shorter operation time and less technically demanding.

The Survivorship of Revision Total Hip Replacement With Severe Proximal Bone Deficiency Using a Modular Taper Fluted Prosthesis

BackgroundContemporary uncemented femoral revision hip systems have become commonly used over the past decade and have enabled the reconstruction of leg length, offset and anteversionas independent variables through the use of modular junctions. Modular junction failures between the proximal body and distal stem have been described withrevision systems, although this is rare. We sought to identify the survivorship of one revision system in a salvage arthroplasty scenario where no host bone support of the modular junction was present.MethodsFrom a series of 136 patients, 15 patients (16 hips) were identified without host bone support of the modular junction with a mean radiological follow up of over 6 years(76 months +/- 35 months).ResultsThere have been no cases of prosthetic fracture over the follow-up duration, withtwo revisions performed for reasons of aseptic loosening and infection. The mean BMI of the study group was 30.2 with 78% of the cohort classified as overweight or obese.ConclusionIt is well recognised that, host bone support of the modular junction is preferable, however the satisfactory outcomes over the midterm in these complex patients suggests that modular revision systems remain an option.

Histopathological Findings of Failed Free Vascularized Fibular Grafting for Osteonecrosis of the Femoral Head after Long-Term Follow-Up

Purpose. The aim of this study was to report the histopathology of failed free vascularized fibular grafting (FVFG) for osteonecrosis of the femoral head (ONFH) after a mean follow-up of 11.5 years (ranged from 10.6 to 14.2 years). Methods. Six hips of 5 patients with a history of steroid use, aged 34–67 years, were in stage II of ONFH as classified by the Ficat and Arlet classification at the time of FVFG treatment. Grafting failure led to osteoarthritis of the hip joint during a mean of 11.5 years of follow-up. Femoral head specimens were first evaluated macroscopically. Bone specimens were sectioned into long strips, divided into necrotic, transitional, and healthy zones, and then prepared for nondecalcified and decalcified histopathological examination using hematoxylin and eosin (HE) staining, Goldner’s trichrome staining, and immunofluorescence (IF) staining. Results. Femoral head articular cartilage surfaces appeared thin, opaque, and partially cartilaginous missing, with gradual collapse detected in weight-bearing areas. The interface with the fibular graft showed well union, with no obvious gaps between graft and host bone, as observed macroscopically. The necrotic area was filled with fibular graft, cancellous bone, and cartilaginous or soft tissue invasion. Histopathology results revealed well integration between fibular graft and host bone, with thickened trabecular bone. Gaps occurred in transitional and healthy zones. In the necrotic zone, cartilaginous or soft tissue invasion occurred, while thin or missing articular cartilage exposed subchondral bone to hip joint surfaces. By IF counterstaining with CD-31 and α-SMA, blood vessel transplanted during fibular grafting could be clearly observed along the graft from healthy to necrotic zones. In the necrotic zone, blood vessels presented obviously and spread into the surrounding area of the graft tip. Conclusion. After FVFG procedure with a mean follow-up of 11.5 years, fibular grafts retained their integrity as viable, vascularized, cortical bone that fused well with host bone and formed thickened trabecular bone surrounding the surface of the graft. However, the revascularization of FVFG’s blood vessels spreading from the tip of the fibular graft into subchondral area of necrotic lesion did not improve significantly in these failure cases. The local necrotic lesion failed to be repaired as healthy trabecular bone to buttress articular surface and was occupied by soft tissues.

Application of autologous cortical bone grafts for femoral non-union fractures in two dogs

Two dogs with non-union fractures and osteomyelitis in the femoral diaphysis were referred to the authors’ hospital. During surgery, the defects were reconstructed using autologous cortical bones harvested from the contralateral femoral diaphysis. Graft fixation was performed by a double-plate technique in both cases. Autogenous cancellous bone was also grafted between the host bone and the graft in both cases. Antibiotics were administered for two to three weeks. In cases 1 and 2, no loosening of the implant or lameness was observed after 31 months and 10 months, respectively. Autologous cortical bone grafts are useful in reconstructing large-sized bone defects of the femoral diaphysis associated with non-union fracture and osteomyelitis.