Modified Shelf Acetabuloplasty Endoscopic Procedure With Allograft for Developmental Hip Dysplasia Treatment

Hip shelf acetabuloplasty in borderline dysplasia, an alternative between Periacetabular Osteotomy and arthroscopic procedures

PURPOSE

Surgical treatments for symptomatic borderline dysplastic hips (Lateral Center-Edge Angle: LCEA 18-25°) remain challenging, instability being the primary issue. Currently, treatment options include arthroscopic procedures or peri-acetabular osteotomy (PAO). Although the popularity of the acetabular shelf bone block has declined in favor of PAO, it may still be relevant as a hip joint stabilizer and coverage area, rather than for increasing coverage area by cartilage. We analyzed clinical and radiographic outcomes of 23 borderline hips after undergoing shelf procedure with a minimum follow-up of two years.

METHODS

This is a retrospective descriptive study. Clinical evaluations (modified Harris Hip Score: mHHS, Non-Arthritic Hip Score: NAHS, International Hip Outcome Tool: iHOT12) and radiographic assessments were performed before and after surgery. We collected data on revision surgery rates, associated surgical procedures (labrum, impingement), complications, arthrosis progression, and conversion to total hip replacement (THR).

RESULTS

The mean LCEA was 21°, and the mean follow-up period was five years (2 to 14 years). Clinical scores showed significant improvement at the last follow-up, mHHS increasing from 47 to 72 (p < 0.001), NAHS from 42 to 68 (p < 0.001), iHOT12 from 28 to 52 (p < 0.001), and pain levels decreasing from 7 to 3. Revision surgery rate was 13%, and complication rate was 8%. No osteoarthritis beyond Tönnis grade 2, and no cases required conversion to THR.

CONCLUSION

Arthroscopic procedures and PAO have shown promising results in the treatment of borderline hips. The hip shelf procedure appears to be a simple and effective treatment for stabilizing borderline hips, with favorable outcomes for 80% of patients and a low rate of arthritic progression. Shelf procedure could be a valuable addition to the therapeutic options for painful borderline dysplasia of the hip.

Arthroscopic Shelf Acetabuloplasty in the Treatment of Acetabular Dysplasia Combined With Cam-Type Femoroacetabular Impingement

Acetabular dysplasia is a hip condition characterized by abnormal development of the acetabulum, which can be present from birth or develop during childhood and may persist into adulthood. Mild or borderline acetabular dysplasia frequently is associated with cam-type femoroacetabular impingement in adults. Over time, the association of impingement and abnormal contact can lead to hip pain, cartilage damage, labral tears, and an increased risk of developing hip osteoarthritis. Several surgical treatments have been proposed: arthroscopic capsular plication, periacetabular osteotomy, or shelf acetabuloplasty. As mini-invasive shelf acetabuloplasty procedure has already proven its effectiveness, an arthroscopic shelf acetabuloplasty represents a less-invasive, less-risky procedure and allows during the same procedure to perform intra-articular resection of the femoral cam, labrum repair and capsular plication. This Technical Note describes an original technique of arthroscopic shelf acetabuloplasty that combines an outside-in arthroscopic approach for the intra-articular procedure (labral repair, femoroplasty, capsular plication) and an endoscopic shelf acetabulopasty with a tricortical iliac crest autograft secure with a single cannulated screw.

Lateral Center-edge Angle of 18° (Bone-Edge): Threshold for Hip Arthroscopy Treatment in Patients with Borderline Developmental Dysplasia of the Hip?

OBJECTIVE

Hip arthroscopy for the treatment of symptomatic borderline developmental dysplasia of the hip (BDDH) has been controversial. The purpose of this study was to retrospectively analyze minimum 2-year outcomes of BDDH after arthroscopic surgery and explore the criteria and thresholds of the lateral center-edge angle (LCEA) in arthroscopic surgery for BDDH.

METHODS

Data were retrospectively collected from patients aged 18-50 who underwent arthroscopic surgery for BDDH and had an LCEA 18-25° between September 2016 and June 2020. The consistency of interobserver and intraobserver measurements of bone-edge LCEA was analyzed. Patients were divided into two groups based on LCEA (18-20°and 20-25°) and the results of arthroscopy compared between groups. Patient-reported outcome (PRO) scores, consisting of the modified Harris hip score (mHHS), the visual analogue scale (VAS) and the international hip outcome tool-12 (IHOT-12), the minimal clinically important difference (MCID) and patient acceptable symptom status (PASS) were calculated.

RESULTS

In 52 patients with ≥2-year follow-up, female patients accounted for 71.2% and the mean age was 30.8 ± 8.4 years (range: 18 to 49 years). There was a high level of agreement when measuring the bone-edge LCEA definition of BDDH (Kappa = 0.921). Interobserver repeatability (ICC = 0.909, 95%CI: 0.847-0.947) and intraobserver repeatability (ICC = 0.944, 95%CI: 0.905-0.968) were excellent for bone-edge LCEA measurements. In addition to LCEA and Tönnis angle, there were no significant differences in α angle, neck stem angle, femoral anteversion angle, medial joint space, Tönnis grade of osteoarthritis, acetabular retroversion (8 sign), Cam deformity and anterior inferior iliac spine (AIIS) morphology between the two groups (p > 0.05). Intraoperative findings and procedures showed no statistical difference between groups (p > 0.05). The mean follow-up time was 44.4 ± 11.0 months (range: 25 to 64 months). Postoperative VAS, mHHS and IHOT-12 scores in the LCEA 18-20° group and the LCEA 20-25° group were significantly improved compared with those before surgery, and there was no statistically significant difference in the percentage of MCID and PASS (mHHS and iHOT-12) between the groups (p > 0.05).

CONCLUSION

Patients in the LCEA 18-20° group and the LCEA 20-25° group achieved favorable outcomes after arthroscopic surgery. LCEA 18° (bone-edge) should be the threshold for hip arthroscopic surgery in BDDH patients without obvious hip instability.

Endoscopic Shelf Procedure and Ischiofemoral Decompression with Arthroscopic Acetabular Labral Reconstruction: A Case Report

CASE

A 43-year-old female patient complained of pain in the right hip. The diagnoses of hip dysplasia, ischiofemoral impingement (IFI), femoroacetabular (FAI) cam-type morphology, and labral tear were made. The patient underwent hip arthroscopy with labral reconstruction for an irreparable labral tear and cam-morphology correction, and hip endoscopy for shelf procedure and ischiofemoral decompression. Favorable outcomes were reported at 1-year follow-up.

CONCLUSION

Hip arthroscopy for FAI cam-type morphology with labral reconstruction and concomitant hip endoscopy for shelf and ischiofemoral decompression seem to be safe for the treatment of active young adult patients with FAI cam-type morphology, irreparable labral tear, dysplasia, and IFI diagnoses. Nevertheless, the results presented should not be extrapolated as this is a case report.

3D-Printed Regenerative Magnesium Phosphate Implant Ensures Stability and Restoration of Hip Dysplasia

Osteoarthritis of the hip is a painful and debilitating condition commonly occurring in humans and dogs. One of the main causes that leads to hip osteoarthritis is hip dysplasia. Although the current surgical methods to correct dysplasia work satisfactorily in many circumstances, these are associated with serious complications, tissue resorption, and degeneration. In this study, a one-step fabrication of a regenerative hip implant with a patient-specific design and load-bearing properties is reported. The regenerative hip implant is fabricated based on patient imaging files and by an extrusion assisted 3D printing process using a flexible, bone-inducing biomaterial. The novel implant can be fixed with metallic screws to host bone and can be loaded up to physiological loads without signs of critical permanent deformation or failure. Moreover, after exposing the hip implant to accelerated in vitro degradation, it is confirmed that it is still able to support physiological loads even after losing ≈40% of its initial mass. In addition, the osteopromotive properties of the novel hip implant is demonstrated as shown by an increased expression of osteonectin and osteocalcin by cultured human mesenchymal stem cells after 21 days. Overall, the proposed hip implant provides an innovative regenerative and mechanically stable solution for hip dysplasia treatment.

Short-term patient-reported outcomes following concomitant hip arthroscopy and the endoscopic modified shelf procedure for the treatment of acetabular dysplasia and intra-articular pathology

The shelf procedure is a treatment of acetabular dysplasia, with the aim of increasing weight-bearing acetabular coverage. Although several shelf techniques have been described, the endoscopic procedure with concomitant hip arthroscopy is a new, less invasive alternative. Outcomes following this procedure are scarce. The purpose of this study was to report short-term patient-reported outcomes (PROs) following concomitant hip arthroscopy and endoscopic modified shelf procedure in the setting of acetabular dysplasia and labral tears. Patients that met extraordinarily selective surgical indications and underwent the abovementioned surgery between February 2016 and October 2019 and had minimum 1-year follow-up were included. There were five females with a mean age of 40.18 ± 5.05 years and follow-up of 21.55 ± 8.68 months. The lateral center-edge angle increased from 15.80° to 23.20° (P = 0.003), and vertical center-edge angle increased from 16.60° to 23.60° (P < 0.001). The Tönnis angle decreased from 15.40° to 3.74° (P < 0.001). The alpha angle decreased from 58.46° to 40.70° (P < 0.001). PROs demonstrated significant improvement at latest follow-up (modified Harris Hip Score, P = 0.042; Non-Arthritic Hip Score, P < 0.001; Hip Outcome Score–Sports Specific Subscale, P = 0.035; Visual Analog Scale, P < 0.001; International Hip Outcome Tool-12, P = 0.043), and satisfaction was 8.60 ± 0.89. No secondary surgeries were reported. Concomitant hip arthroscopy and endoscopic modified shelf procedure appears to be a safe and effective procedure for patients with acetabular dysplasia and labral tears yielding favorable outcomes and satisfaction at short-term follow-up.

Risk Factors for Intraoperative Periprosthetic Femoral Fractures in Patients with Hip Dysplasia Undergoing Total Hip Arthroplasty with Uncemented Prostheses

OBJECTIVES

To determine the potential risk factors for intraoperative periprosthetic femoral fractures in patients with developmental dysplasia of the hip (DDH) undergoing total hip arthroplasty (THA).

METHODS

This was a retrospective study. Patients who were diagnosed with DDH and undergoing THA (by artificial joint replacement) at our hospital from January 1999 to December 2019 were included in this study. Clinical and radiological factors were obtained from their medical records, such as age, sex, Crowe classification, morphological features of proximal femur, and features of surgical procedure. The outcome of interest was the occurrence of intraoperative periprosthetic femoral fracture, which was recorded and classified according to the Vancouver classification system. According to the fracture status, the patients were divided into two groups: the fracture group and the non-fracture group. Multivariate logistic regression model was built to identify the risk factors for these fractures.

RESULTS

A total of 1252 hips were finally included. Intraoperative periprosthetic femoral fractures were identified in 62 hips. The incidence of intraoperative periprosthetic femoral fractures in patients with DDH undergoing THA was 4.95%. There were 22 patients (proportion = 35.48%, incidence = 1.76%) with Type A fractures, 38 (proportion = 61.29%, incidence = 3.04%) with Type B fractures, and two (proportion = 3.23%, incidence = 0.16%) with Type C fractures. Six independent risk factors for intraoperative periprosthetic femoral fractures were identified: osteoporosis (OR = 3.434; 95% CI, 1.963-6.007), previous surgical history (OR = 4.797; 95% CI, 2.446-9.410), Dorr Type A canal (OR = 3.025; 95% CI, 1.594-5.738), retained femoral neck length (OR = 1.121; 95% CI, 1.043-1.204), implanted metaphyseal-diaphyseal fixation stems (OR = 3.208; 95% CI, 1.562-6.591), and implanted stem with anteversion design (OR = 2.916; 95% CI, 1.473-5.770).

CONCLUSIONS

The overall incidence of intraoperative periprosthetic femoral fractures in patients with DDH undergoing THA was 4.95%, which was at a moderate level compared to patients with other diseases undergoing THA. Six independent risk factors were identified: osteoporosis, previous surgical history, Dorr Type A canal, insufficient neck osteotomy level, implantation of metaphyseal-diaphyseal fixation stem, and implantation of a stem with an anteversion design. Comprehending these risk factors might help surgeons prevent the occurrence of these intraoperative periprosthetic femoral fractures in patients with DDH.

On-lay grafting of a calcium hydroxyapatite bone substitute: A preliminary animal experimental study

BACKGROUND

Bone substitutes are widely accepted for various clinical applications. However, the usage is predominantly intraosseous implantation, whereas extraosseous on-lay grafting is rare and lacks scientific evidence. The purpose of this study is to elucidate whether osteoconduction occurs in on-lay grafted bone substitute.

METHODS

Custom-made interconnected porous calcium hydroxyapatite ceramic (IPCHA) was on-lay grafted with screw or anchor fixation (S- and A-groups, respectively) at the anterior aspect of the femur of skeletally mature Japanese white rabbits. At 3, 6 and 12 weeks postoperatively, 4 samples for each time point and each group were evaluated by microfocus computed tomography (micro-CT) and histology.

RESULTS

Volume-rendered three-dimensional micro-CT images showed a high-density calcified area infiltrating IPCHA from the femoral cortex as of 6 weeks. When quantified, the calcified volume per unit volume first showed no difference between the two groups at 3 weeks but increased over time, and became significantly greater in the S-group than in the A-group (p = 0.012 and 0.004 at 6 and 12 weeks, respectively). Histologically, IPCHA pores were first occupied by fibrous tissue at 3 weeks; then, the pores adjacent to the femoral cortex were gradually replaced by bony tissue as of 6 weeks for both fixations.

CONCLUSIONS

IPCHA allowed new bone formation inside the material even though it was implanted in an on-lay fashion on the cortical bone. Our results suggested that on-lay grafted IPCHA exerted its osteoconductivity well, with more new bone forming in screw-fixated samples than in anchor-fixated samples.

Three-Dimensional Navigation (O-arm) for Minimally Invasive Shelf Acetabuloplasty

Hip dysplasia is an important cause of osteoarthritis in young adults. For these patients, conservative treatment is an interesting alternative to arthroplasty. The current literature suggests better clinical and functional outcomes when shelf acetabuloplasty is performed for a moderate joint pinch (<50%) associated with an important external coverage defect of the acetabular cup (<25°). Compared with open surgical procedures, minimally invasive surgical techniques or arthroscopy tend to reduce morbidity. To date, the major intraoperative difficulty remains the positioning of the graft. This Technical Note aims to outline a minimally invasive shelf acetabuloplasty, with optimization of the position of the autologous iliac crest bone graft using 3-dimensional navigation.

Small Molecules Enhance Scaffold-Based Bone Grafts via Purinergic Receptor Signaling in Stem Cells

The need for bone grafts is high, due to age-related diseases, such as tumor resections, but also accidents, risky sports, and military conflicts. The gold standard for bone grafting is the use of autografts from the iliac crest, but the limited amount of accessible material demands new sources of bone replacement. The use of mesenchymal stem cells or their descendant cells, namely osteoblast, the bone-building cells and endothelial cells for angiogenesis, combined with artificial scaffolds, is a new approach. Mesenchymal stem cells (MSCs) can be obtained from the patient themselves, or from donors, as they barely cause an immune response in the recipient. However, MSCs never fully differentiate in vitro which might lead to unwanted effects in vivo. Interestingly, purinergic receptors can positively influence the differentiation of both osteoblasts and endothelial cells, using specific artificial ligands. An overview is given on purinergic receptor signaling in the most-needed cell types involved in bone metabolism-namely osteoblasts, osteoclasts, and endothelial cells. Furthermore, different types of scaffolds and their production methods will be elucidated. Finally, recent patents on scaffold materials, as wells as purinergic receptor-influencing molecules which might impact bone grafting, are discussed.