Operative treatment of avascular necrosis of the femoral head after slipped capital femoral epiphysis

Long-term results of valgus intertrochanteric osteotomy for partial avascular necrosis of the femoral head after femoral neck fracture in adolescents

PURPOSE

The study evaluates long-term results in patients treated by valgus intertrochanteric osteotomy (VITO) for partial avascular necrosis of the femoral head (ANFH) after fracture of the femoral neck in adolescent age. Although this method is mentioned in literature frequently, there are only few studies in the literature dealing with it in detail.

METHODS

Authors evaluated five patients at the interval of 15 to 20 years following VITO. The mean age of the patients at the time of injury was 13.6 years and at the time of VITO 16.7 years. The studied parameters included resorption of necrotic segment of femoral head, development of posttraumatic osteoarthritis and leg shortening.

RESULTS

Comparison of radiographs and MRI scans before and after VITO showed resorption of the necrotic segment of the femoral head and its remodeling in all five patients. However, two patients gradually developed slight osteoarthritic changes. In one patient, remodeling of the femoral head occurred during the first 6 years postoperatively. Subsequently, the patient developed severe osteoarthritis with marked clinical symptoms.

CONCLUSION

VITO can improve the long-term function of the hip joint in adolescents with ANFH after a femoral neck fracture, but cannot restore completely the original shape and structure of the femoral head.

Minifragment plating of the fibula in unstable ankle fractures

INTRODUCTION

Only 6.4-17% of the load is transmitted through the fibula when weight-bearing. Plate fixation of distal fibular fractures using minifragments (≤ 2.8 mm) could lead to similar reduction with less implant removal (IR) rates, compared to small-fragment plates (3.5 mm). We hypothesized that the use of minifragment plates is at least similar in unscheduled secondary surgery.

MATERIALS AND METHODS

In this retrospective cohort study, all patients with surgically treated distal fibular fractures between October 2015 and March 2021 were included. Patients treated with plate fixation using minifragments and patients treated with small-fragment plates were compared regarding the following outcomes: secondary dislocation, malreduction, implant malposition, nonunion, surgical site infections (SSI) and IR.

RESULTS

Sixty-five patients (54.2%) received a minifragment implant (≤ 2.8 mm) and 55 patients (45.8%) received a small-fragment implant (3.5 mm). There were no patients needing secondary surgery in the minifragment group compared to 9 patients following fixation using small-fragment implants (3 with secondary dislocation, 5 with malreduction and 1 with malposition, p = 0.001). SSI rates were 3.1% for minifragment and 9.1% for small-fragment implants (p = 0.161). Implant removal was performed significantly less often following use of minifragment implants (17.8% and 53.2%, p < 0.001).

CONCLUSIONS

In this cohort, minifragment plate fixation for distal fibular fractures is an adequate fixation method offering stable fixation with significant lower need for implant removal and comparable complications to small-fragment plates, although an adequately powered randomized controlled study is needed for implementation in a clinical setting.

LEVEL OF EVIDENCE

Therapeutic, III.

Operative Management of Avascular Necrosis of the Femoral Head in Skeletally Immature Patients: A Systematic Review

Purpose: Osteonecrosis of the femoral head (ONFH) is common in skeletally immature patients. The management of ONFH is controversial, with limited evidence and unpredictable results. This study systematically reviewed the current operative modalities and clinical outcomes of surgical management for ONFH in skeletally immature patients. Methods: The present study was conducted according to the PRISMA 2020 guidelines. PubMed, Google Scholar, Embase, and Web of Science databases were accessed in October 2021. All the published clinical studies reporting data concerning the surgical management of ONFH in skeletally immature patients were included. Results: This review included 122 patients (127 hips). 38.2% (46 of 122) were female. The mean age of the patients was 14.2 ± 2.3 years. The mean duration of the follow-up was 55.3 ± 19.6 months. The Harris Hip Score improved from 68.8 ± 11.9 at baseline to 90.5 ± 6.5 at last follow-up (p < 0.0001). Femoral head collapse and secondary hip degeneration were the most common complications. Conclusion: Several surgical techniques are available and effective for the management of ONFH in skeletally immature patients. This study evidenced high heterogeneity of the surgical procedures and eligibility criteria. Further high-quality investigations are required to establish proper indications and surgical modalities.

Bone Regeneration and Angiogenesis by Co-transplantation of Angiotensin II-Pretreated Mesenchymal Stem Cells and Endothelial Cells in Early Steroid-Induced Osteonecrosis of the Femoral Head

Mesenchymal stem cells (MSCs) have been shown to exert a positive impact on osteonecrosis of the femoral head (ONFH) in preclinical experiments and clinical trials. After the femoral head suffers avascular necrosis, the transplanted MSCs undergo a great deal of stress-induced apoptosis and senescence in this microenvironment. So, survival and differentiation of MSCs in osteonecrotic areas are especially important in ONFH. Although MSCs and endothelial cells (ECs) co-culture enhancing proliferation and osteogenic differentiation of MSCs and form more mature vasculature in vivo, it remains unknown whether the co-culture cells are able to repair ONFH. In this study, we explored the roles and mechanisms of co-transplantation of angiotensin II (Ang II)-MSCs and ECs in repairing early ONFH. In vitro, when MSCs and ECs were co-cultured in a ratio of 5:1, both types of cells managed to proliferate and induce both osteogenesis and angiogenesis. Then, we established a rabbit model of steroid-induced ONFH and co-transplantation of Ang II-MSCs and ECs through the tunnel of core decompression. Four weeks later, histological and Western blot analyses revealed that ONFH treated with Ang II-MSCs and ECs may promote ossification and revascularization by increasing the expression of collagen type I, runt-related transcription factor 2, osteocalcin, and vascular endothelial growth factor in the femoral head. Our data suggest that co-transplantation of Ang II-MSCs and ECs was able to rescue the early steroid-induced ONFH via promoting osteogenesis and angiogenesis, which may be regarded as a novel therapy for the treatment of ONFH in a clinical setting.

Purposeful Closed Reduction and Pinning in Unstable Slipped Capital Femoral Epiphysis Results in a Rate of Avascular Necrosis Comparable to the Literature Mean

The standard treatment of stable slipped capital femoral epiphysis (SCFE) is generally accepted to be in situ pinning. Controversy exists regarding the treatment of unstable SCFE, including the role of a purposeful closed reduction or open reduction. The objective of this study was to investigate the rate of avascular necrosis (AVN) with purposeful closed reduction and in situ pinning of unstable SCFE. The authors retrospectively reviewed 221 patients with 302 SCFE hips treated with in situ pinning between 2000 and 2014. Forty-eight patients (50 hips) presented with an unstable SCFE. All unstable SCFEs were treated by a gentle reduction method with traction and hip internal rotation followed by pinning. Southwick angles were measured prior to reduction and at the first postoperative visit. No stable SCFEs developed AVN. Thirteen (26%) unstable SCFEs developed AVN. Avascular necrosis developed in 7 of 17 (41%) hips screened with magnetic resonance imaging vs 6 of 33 (18%) hips screened with plain radiographs alone. Mean change in Southwick angle was 28°±8° in the AVN group vs 18°±18° in the no AVN group (P=.18). Despite potentially inflating the rate with the use of early detection magnetic resonance imaging, the authors found an AVN rate comparable to that in the published literature with the use of gentle purposeful reduction on a fracture table, and no statistical differences in reduction amount between patients with and without AVN. Gentle purposeful reduction appears to be a reasonable low morbidity option in the treatment of unstable SCFE without a clear increase in risk of AVN. [Orthopedics. 2021;44(2):92-97.].

Avascular necrosis post unstable slipped capital femoral epiphysis: a treatment algorithm with staged hinged hip distraction: mid-term results

BACKGROUND

Management of avascular necrosis (AVN) of the femoral head in slipped capital femoral epiphysis (SCFE) is difficult. We proposed to ascertain if staged hip distraction could prevent collapse and recover the femoral head.

METHODS

A retrospective review of the hip database retrieved 16 children with unstable SCFE and AVN. All underwent capital realignment by surgical dislocation followed by 2nd-stage hinged hip distraction. Patient demographics and radiographic parameters of deformity, AVN and arthritis were collected. The patients scored their hip function both before and after intervention and at follow-up using the modified Harris Hip Score and Nonarthritic Hip score.

RESULTS

7 boys and 9 girls formed the study group (n = 16). The average age at surgery was 12.7 years (9-16 years). 8 rights hips and 8 left hips were involved. The average follow-up was 45 months (33-66 months). Group A (n = 7) had hip distraction only if the follow-up radiographs showed AVN changes and collapse. Based on the observations in Group A, the protocol was changed for Group B. Group B (n = 9) underwent hip distraction at 6 weeks of capital realignment for avascularity of the femoral head. In Group A, all patients had further collapse and advanced arthritis at follow-up. In Group B all patients had hip joint space restored and good hip function without pain at follow-up.

CONCLUSIONS

Pre-emptive application of hip distractor for those children with proven lack of blood flow to the femoral head is a potential option to stall the progression of AVN and to help recover useful hip function.

Angiogenesis and bone regeneration by mesenchymal stem cell transplantation with danshen in a rabbit model of avascular necrotic femoral head

The present study aimed to explore the potential of combined treatment with mesenchymal stem cells (MSCs) and danshen for angiogenesis and bone regeneration in a rabbit model of avascular necrosis of femoral head (ANFH). A rabbit model of ANFH was established using the Shwartzman reaction with methylprednisolone and Escherichia coli endotoxin injection. Magnetic resonance imaging (MRI) and histopathological examination were used to evaluate the rabbit model of ANFH. The rabbits were randomly divided into the danshen group, the MSCs group, the danshen combined with MSCs group and the model group (treated with physiological saline). The expression level of monocyte chemoattractant protein-1 (MCP-1) and stromal cell-derived factor-1 (SDF-1) were determined by reverse transcription polymerase chain reaction (RT-PCR). The expression level of bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF) were detected by immunofluorescence and the mRNA expression of BMP-2 and VEGF were detected by RT-PCR. Typical osteonecrosis occurred in the rabbit model of ANFH, which indicated that the model was successfully established. MCP-1 and SDF-1 were significantly increased in the model group compared with the normal group (P<0.05). Following the administration of MSCs and Salvia miltiorrhiza (danshen), MSCs labeled with 5-bromo-2-deoxyuridine were observed to be gathered in the necrotic area. The increased migration of MSCs to the necrotic area may be due to the upregulated expression of the chemokines MCP-1 and SDF-1. ANFH treated with danshen combined with MSCs may promote revascularization by increasing the expression of VEGF and BMP-2 in the femoral head, promoting re-ossification and revascularization. Danshen combined with the transplantation of MSCs may be regarded as a novel therapy for the treatment of ANFH in a clinical setting.

Transtrochanteric rotational osteotomy for avascular necrosis of the femoral head after unstable slipped capital femoral epiphysis: 10-year clinical results

BACKGROUND

Avascular necrosis of the femoral head (AVN) is the most serious complication after unstable slipped capital femoral epiphysis (SCFE), and is often unsalvageable. We report a minimum 10 years of clinical results for transtrochanteric rotational osteotomy of the femoral head (TRO) for AVN.

METHODS

This study included 7 patients (7 hips) with a mean age at surgery of 13.3 years, and the follow-up period was 15.8 years. All patients had prior treatment via closed reduction and pinning of the unstable SCFE, and showed severely collapsed femoral heads. The direction of rotation was anterior in 3 hips and posterior in 4. The Merle d'Aubigné-Postel score (MDPS) was used for clinical assessment, and joint degeneration was assessed with the Kellgren and Lawrence classification (KL-grade).

RESULTS

The spherical intact area of the femoral head was moved to the weight-bearing portion, and subluxation was corrected via rotation combined with intentional varus positioning. The mean MDPS improved from 10.3 points to 15.6 points at 5 years, and it was maintained at 15.0 points by 10 years; 3 hips were excellent, 1 was good, 2 were fair, and 1 showed poor outcomes. No patient experienced re-collapse after TRO or required conversion to hip replacement or arthrodesis. After 10 years, degenerative changes became evident over time, and 2 hips progressed to KL-4 with a decreased MDPS.

CONCLUSIONS

Although some joint degeneration is inevitable in the long-term, TRO is an effective salvage procedure for treating AVN after unstable SCFE.

Slipped capital femoral epiphysis: prevalence, pathogenesis, and natural history

BACKGROUND

Obesity is a risk factor for developing slipped capital femoral epiphysis (SCFE). The long-term outcome after SCFE treatment depends on the severity of residual hip deformity and the occurrence of complications, mainly avascular necrosis (AVN). Femoroacetabular impingement (FAI) is associated with SCFE-related deformity and dysfunction in both short and long term.

QUESTIONS/PURPOSES

We examined obesity prevention, early diagnosis, reducing AVN and hip deformity as strategies to reduce SCFE prevalence, and the long-term outcomes after treatment.

METHODS

A search of the literature using the PubMed database for the key concepts SCFE and treatment, natural history, obesity, and prevalence identified 218, 15, 26, and 49 abstracts, respectively. WHERE ARE WE NOW?: A correlation between rising childhood obesity and increasing incidence of SCFE has been recently reported. Residual abnormal morphology of the proximal femur is currently believed to be the mechanical cause of FAI and early articular cartilage damage in SCFE. WHERE DO WE NEED TO GO?: Reducing the increasing prevalence rate of SCFE is important. Treatment of SCFE should aim to reduce AVN rates and residual deformities that lead to FAI to improve the long-term functional and clinical outcomes. HOW DO WE GET THERE?: Implementing public health policies to reduce childhood obesity should allow for SCFE prevalence to drop. Clinical trials will evaluate whether restoring the femoral head-neck offset to avoid FAI along with SCFE fixation allows for cartilage damage prevention and lower rates of osteoarthritis. The recently described surgical hip dislocation approach is a promising technique that allows anatomic reduction with potential lower AVN rates in the treatment of SCFE.

Outcomes of total hip replacement in patients with slipped capital femoral epiphysis

BACKGROUND

Total hip replacement has been advocated for the treatment of degenerative hip diseases secondary to slipped capital femoral epiphysis; nonetheless, outcomes of this procedure have not been well established. We reviewed the outcomes of modern total hip replacements in patients who suffered from slipped capital femoral epiphysis.

METHODS

A retrospective study was carried out on 32 total hip replacements performed on 28 patients who suffered from slipped capital femoral epiphysis from August 1994 to January 2007. The average age at the time of surgery was 45 years. Clinical evaluation was performed using the Harris Hip Score, radiographic assessment measuring cup and stem orientation, the extent of osteolysis around the implant, and leg length discrepancy. The average follow-up was 98 months (range 25-204 months).

RESULTS

Two total hip replacements failed, one for stem aseptic loosening and the other for modular neck failure. The cumulative survival rate at 9 years was 92.8 %. If the end point was revision for implant loosening, the survival rate improved to 96.8 % at 9 years. The only complication recorded was an intraoperative fracture of the lesser trochanter immediately treated with cerclage wire. At the latest follow-up, the Harris Hip Score averaged 86 (range 70-97). Leg length discrepancies greater than 1 cm were present in 18 cases before surgery, and in only 6 cases after surgery.

DISCUSSION

We recommend total hip replacement for patients who suffer from slipped capital femoral epiphysis because of the satisfactory survival, low complication rate, and the possibility of restoring leg length.

Valgus intertrochanteric osteotomy for coxa vara of Bucholz-Ogden Types II and III in patients older than 30 years

BACKGROUND

Ischemic necrosis of the proximal femur resulting in coxa vara is a severe iatrogenous complication of the treatment of developmental dysplasia of the hip (DDH). Severe relative overgrowth of the greater trochanter and reduction of the neck result in insufficiency of hip abductors. Unequal limb length causes obliquity of the pelvis, compensatory scoliosis of the lumbar spine and valgus deformity of the ipsilateral knee. The purpose of this study was to investigate the effect of valgus intertrochanteric osteotomy in patients with coxa vara older than 30 years.

METHODS

Fifteen female patients of the average age 43 years (range 31-60) with postdysplastic varus deformity of the proximal femur and shortening of affected limb of 2-4 cm were treated with valgus intertrochanteric osteotomy. None of them was operated on before. In eight cases, the varus deformity of the proximal femur was evaluated as Bucholz-Ogden Type II, in seven cases as Bucholz-Ogden Type III. The average follow-up was 10 years (range 5-20).

RESULTS

By the time of the last functional follow-up, three patients had already underwent conversion of osteotomy to total hip arthroplasty (THA), namely, 7.5, 11, and 12 years after osteotomy. All the patients evaluated the effect of osteotomy positively, including those treated later with THA. The average preoperative Harris Hip Score was 83, the postoperative one was 93.

CONCLUSIONS

Based on results, the valgus intertrochanteric osteotomy appears to be a reliable treatment for postdysplastic coxa vara in patients older than 30 years.