[Abstract] Objective To investigate the effective treatment of severe inversion deformity of the proximal femur with fibrous dysplasia (FD). Methods From January 2001 to December 2011, 26 patients with FD with severe proximal femoral hip inversion with shortened limb deformity were admitted. The relative length of the femur was 2.0-9.5 cm shorter than that of the contralateral side, with an average of 4.2 cm. 26 cases underwent exostosis osteotomy near the apex of the proximal femoral deformity, compression bone grafting of the femoral head, neck and osteotomy break, and fixation with inserted and repositioned DHS or DCS plates. Results Twenty-three cases were followed up after surgery, and the follow-up time ranged from 6 months to 10.5 years, with an average of 4.8 years. 22 cases had reliable internal fixation, and one case with a DHS internal fixator femoral head threaded nail cut out 2 mm of the femoral head 1 year after surgery, which was painful and cured after removal of the internal fixation. All the femoral force lines were basically corrected, the osteotomy surface reached bony healing, the neck stem angle of hip inversion deformity was corrected to 95-130°, averaging 119°, the relative length of femur was lengthened 2.5-8.6 cm after correction compared with that before surgery, averaging 3.7 cm, and the preoperative limb shortening was basically corrected. After surgery, 17 patients had normal gait; 2 walked with a single crutch and 5 walked without a crutch with a mild limp. Postoperatively, pain disappeared in 19 cases and was significantly reduced in 4 cases. All patients had no infection, re-fracture or deformity progression. Conclusion Severe hip inversion with shortened limb deformity in proximal femoral FD is a simple and effective treatment with external osteotomy near the apex of the proximal femoral deformity, compression-type bone grafting of the femoral head, neck and osteotomy break, and fixation with insertion and repositioning DHS or DCS plates. At the same time, the lengthened DHS or DCS plate of the proximal femur has a significant strengthening effect on the bone structure of FD patients, especially maintaining the anatomical force line of the proximal femur and the neck stem angle can play a great role to avoid deformity recurrence.
【Key words】Proximal femur, fibrous dysplasia, severe hip inversion deformity, valgus osteotomy, DHS plate internal fixation
Fibrous dysplasia (FD) is a group of tumor-like disorders characterized by bone fiber degeneration, accounting for approximately 7% of tumor-like diseases [1]. The clinical presentation of FD is complex and varied, and can present as solitary FD, multiple PD, and McCune-Albright syndrome (MAS). From January 2001 to December 2011, we surgically treated 26 patients with severe inversion deformity of the proximal femur with limb shortening and obtained good results. The results are reported as follows.
1. Clinical data
1.1 General data
There were 9 male cases and 17 female cases in this group; age ranged from 8 to 58 years old, with an average of 28 years old. There were 9 cases of unilateral and 17 cases of double. There were 6 cases of uni-bone type and 20 cases of multi-bone type. All patients had hip pain, 13 of them walked with crutches, 3 had pathological fracture and could not walk, 7 had limp without crutches, and 3 had normal gait. Twelve of them had a history of pathological fracture, and eight of them had undergone one to four operations in outside hospitals. The duration of disease in this group of patients ranged from 4 months to 36 years, with an average of 10.3 years.
1.2 Surgical method
The patient was placed in a supine position with the affected side slightly padded, and the proximal femur was approached by a straight lateral incision to expose the proximal femur and protect the surrounding soft tissues and periosteum, and a 2.5-mm diameter guide pin was driven into the center of the femoral neck at the greater trochanter first, and the C-arm or G-arm X-ray machine was used to check whether the center of the femoral neck and the femoral head were in the frontal and lateral positions, and the length was measured and screwed into the threaded nail of the power hip (DHS) or power condyle (DCS). The DHS or DCS plate should be inserted according to the preoperative measurement and design, and then osteotomy should be performed according to the preoperative design template near the apex of the femoral deformity in the subtrochanteric region, as patients with severe deformity are often accompanied by changes in the anteversion angle of the femoral neck and rotational deformity of the femoral axis, the osteotomy should be corrected at the same time. If the deformity is serious, the gluteus medius muscle and surrounding contracted tissues can be released with a sharp knife point; if the femoral destruction is more serious, the femoral distance has been destroyed and the bone quality is poor, the osteotomy should be performed by inward and outward osteotomy, and the osteotomy Because of the extensive femoral lesions and thin bone quality, a lengthened DHS or DCS plate should be used as much as possible, but the screws should not be too full, so as to achieve a wide and secure fixation range and easy healing.
1.3 Postoperative treatment
Antibiotics were routinely used for 1 to 3 days after surgery, and quadriceps isometric contraction exercises and passive hip and knee activities were started 24 to 36 hours after the drainage tube was removed. For the preoperative inversion deformity and limb shortening serious postoperative inversion restriction and abduction deformity can be used in the healthy side lying position with padding between the legs to gradually reduce the method to stretch the contracted gluteus medius and lateral contracture tissue. After 2 weeks of postoperative stabilization of the bone graft area, the affected limb could be partially weight-bearing with a walker; regular follow-up X-rays were performed at 1, 3, 6 and 12 months after surgery.
2.Results
All intraoperative lesions were diagnosed as FD by pathological examination. 23 of the 26 cases were followed up for 6 months to 10.5 years, with an average of 4.8 years. Postoperative radiographs showed that 23 patients with severe hip inversion with shortened limb deformity of proximal femoral FD were treated with external osteotomy near the apex of the proximal femoral deformity, compression-type bone grafting of the femoral head, neck and osteotomy break, and internal fixation was reliable in 22 patients with embedded repositioning DHS or DCS plate fixation, and in one patient, 2 mm of the femoral head was cut out one year after the DHS internal fixation of femoral head threaded nail, which was painful and cured after removal of the internal fixation. The pain was cured after removal of the internal fixation. Most patients had mild bone resorption in the bone graft area at 6 months after surgery, and the bone structure in the bone graft area became dense at 9-16 months. In patients with severe proximal femoral FD with limb shortening deformity, the femoral force line was basically corrected, and the osteotomy surface reached bony healing, and the neck stem angle of hip inversion deformity was corrected to 95-130°, with an average of 119°, and the relative length of femur was lengthened 2.5-8.6 cm, with an average of 3.7 cm, compared with that before surgery. After surgery, 17 patients had normal gait; 2 walked with a single crutch and 5 walked without a crutch with a mild limp. Postoperatively, pain disappeared in 19 cases and was significantly reduced in 4 cases. There was no infection, re-fracture or deformity progression in all patients. If there were no complications caused by the internal fixation plate, it was recommended that the plate should not be removed permanently, because the lengthened DHS or DCS plate at the proximal femur has a significant strengthening effect on the bone structure of FD patients, especially maintaining the anatomical force line of the proximal femur and the cervical stem angle can play a great role in order to avoid the recurrence of deformity.
3. Discussion
The treatment of proximal femoral FD is mainly determined by the extent and degree of the lesion. Due to the partial destruction of the anatomical structure of the diseased femur and the reduction of biomechanical strength, as the lesion continues to progress, the patient’s long-term weight bearing and periprosthetic muscle pulling tend to cause pathological fracture of the femur and aggravate the pain and inversion deformity of the affected hip. Therefore, the key to the treatment of proximal femoral FD is: (1) early detection and treatment to prevent further development of the lesion; (2) adequate bone grafting at the head and neck of the femur to prevent collapse of the femoral head and improve the bone strength and anatomical structure of the femur; (3) reasonable and strong internal fixation to promote bone healing and prevent the reoccurrence of pathological fractures; and (4) osteotomy and orthopedics to fully restore the biological force line of the femur.
Lesion scraping and bone grafting is the main method of treatment for all FD, but it is less effective in patients with multiple and extensive lesions and poor bone strength. Lejman et al [3] concluded from an analysis of the outcome of femoral FD patients with fractures and deformities that the lesion removal graft alone is often ineffective and that osteotomy and internal fixation with Rush nails can achieve good results. In our group of 26 patients, 23 patients with severe proximal femoral FD with shortened limb deformity were followed up by external osteotomy near the apex of the proximal femoral deformity, compression implantation of the femoral head, neck and osteotomy, and internal fixation by inserting and resetting long DHS or DCS plates in 22 patients, suggesting that this method is effective in patients with severe proximal femoral inversion deformity, extensive lesions and poor bone strength. Enneking et al. (1986) concluded that weight-bearing bones with eccentric moments nearby (e.g., femoral neck) should be treated aggressively surgically, and cortical bone grafting can be used to improve the strength of the diseased bone and prevent pathological fractures; it also emphasized that the diseased bone has the same bone healing capacity as normal bone after pathological fracture in the same anatomical region. In this group, both autologous bone and allogeneic bone implanted had different degrees of bone resorption, but the total bone quality and bone strength were significantly improved compared with the original diseased bone; meanwhile, the bone healing ability of the osteotomy surface or pathological fracture was comparable to that of normal bone, indicating that high-quality compression bone graft could improve the bone strength of the diseased area and contribute to the healing of the pathological fracture and osteotomy section.
In patients with proximal femoral FD with hip inversion deformity, an inward displacement osteotomy with external rotation has been used to prevent re-fracture due to stress concentration after simple external rotation osteotomy orthopedic surgery. Guille et al. (1984) treated five cases of proximal femoral FD with internal fixation using inter-rotor oblique adductor osteotomy with embedded implant screws, but due to the poor stability of the osteotomy area, the hip had to be fixed in a “herringbone” type cast for 4 months after surgery. The results showed that this method could effectively avoid stress concentration, prevent pathological fractures, improve gait and stability, and prevent further aggravation of the deformity.
The choice of internal fixation for FD of the proximal femur is not yet uniform [4-15]. Traditional plate screw internal fixation is less effective in patients with extensive lesions and poor bone strength because the site fixed by the plate screw is often the lesion area, where the bone cortex is thin and the fixation arm is short, and the internal fixation is prone to loosening. Freeman et al. (1987) used osteotomy and Zickel nail intramedullary fixation to treat patients with proximal femoral FD with hip inversion deformity. He concluded that the Zickel nail was fixed intramedullary to the distal femur after osteotomy orthopedics, which reduced the distal stress concentration and restored the cervical stem angle effectively through femoral neck fixation. However, the biggest disadvantage of Zickel nail is that there is only one proximal compression locking nail, which cannot prevent the rotation of the head and neck, so it is not suitable for the osteotomy of femoral rotor area or subrotor area, and the distal end of Zickel nail has no locking nail, which cannot prevent the distal rotation of the limb after osteotomy. In recent years, some scholars have analyzed the treatment results of patients with proximal femoral FD and concluded that for those with extensive proximal femoral lesions and poor bone strength, or those with severe hip inversion deformity who undergo osteotomy, strong internal fixation must be used to maintain the proximal femur in a position more in line with the biomechanical axis of the femur in order to promote bone healing and reduce the postoperative recurrence rate. To achieve the above criteria, appropriate internal fixation must be selected. The lengthened DHS or DCS plate fixation system has a strong fixation effect, i.e., it overcomes the inability of the pure anatomical plate to maintain the force line of the cervical stem angle, and solves the risk of extensive lesions of the femur with a wide medullary cavity and thin bone cortex, which makes it difficult to insert and maintain the stability of the intramedullary pin in the proximal femur, and it is simple and easy to master.
In our group of 26 cases, the postoperative neck stem angle and relative length of the femur were significantly corrected in 23 cases of severe hip inversion deformity compared with the preoperative period, and most of the patients had disappeared pain and normal gait. We believe that if the hip inversion deformity angle is <100°, we should try to osteotomy to restore its biological force line, in order to effectively prevent pathological fracture and improve the function of the affected limb; if we only use lesion scraping and bone grafting, we cannot fundamentally solve hip pain, claudication and pathological fracture.
For severe hip entropion deformity with neck stem angle <60° and osteophyte formation below the femoral head (as in Figure 1) and severe limb shortening: if we continue to use DHS plate and strive to restore the neck stem angle to 120°, at this time, the hip head and socket occlusion has been mismatched and the gluteus medius muscle tension will be greater, and even excessive limb lengthening will cause sciatic nerve symptoms. We used DCS plate to reduce the cervical stem angle to 95-105° in these patients, and after surgery, the patient's hip head and socket occlusion basically matched, and the gluteus medius muscle could be adapted by mild release, and the risk of sciatic nerve injury was also reduced. 6 out of 26 cases we used DCS plate, and all of them achieved satisfactory results after surgery.
Figure 1 Female, 18 years old, with preoperative limb shortening of 9 cm Figure 2 Postoperative force line correction
Figure 3 Postoperative limb equilibrium
Figure 4 Female, 17 years old, with 4 cm of preoperative limb shortening Figure 5 Limb isometric and healed at the osteotomy 2 years after surgery
Figure 6 Female, 21 years old, bilateral DF Figure 7 Normal force line and good healing of osteotomy 5 years after surgery
References
1 Chow LT, Griffith J, Chow WH, et al. Arch Orthop Trauma Surg, 2000; 120(7-8): 460464.648-658.
2 Guille JT, Kumar SJ, MacEwen GD. Fibrous dysplasia of the proximal part of the femur. long-term results of curettage and bone-grafting and mechanical J Bone Joint Surg (Am), 1998, 80(5):648-658.
3 Lejman T, Sulko J. Orthopedic management in children with brous dysplasia of bone. Chir Narzadow Ruchu Ortop Pol, 1999, 64(3):303-310.
4 Campanacci M. Bone and soft tissue tumors: clinical features, imaging, pathology and treatment. 2nd ed. New York: Springer, 1999: 88-101.
5 Parekh SG, Donthineni-Rao R, Ricchetti E, et al. Fibrous dysplasia. J Am Acad Orthop Surg, 2004, 12(5): 305-313.
6 DiCaprio MR, Enneking WF. Fibrous dysplasia. Pathophysiology, evaluation, and treatment. J Bone Joint Surg (Am), 2005, 87(8):1848-1864
7 Kumta SM, Leung PC, Griffith JF, et al. Vascularized bone grafting for brous dysplasia of the upper limb. J Bone Joint Surg (Br), 2000, 82(3): 409-412.
8 O’Sullivan M, Zacharin M. Intramedullary rodding and bisphospho-nate treatment of polyostotic brous dysplasia associated with the McCune-Albright syndrome. J Pediatr Orthop, 2002, 22(2): 255-260.
9 Jung ST, Chung JY, Seo HY, et al. Multiple osteotomies and intramed-ullary nailing with neck cross-pinning for shepherd’s crook deformity in polyostotic brous dysplasia: 7 femurs with a minimum of 2 years follow-up. Acta Orthop, 2006, 77(3): 469-473.
10 Chen WJ, Chen WM, Chiang CC, et al. Shepherd’s crook deformity of polyostotic brous dysplasia treated with corrective osteotomy and dynamic hip screw. J Chin Med Assoc, 2005, 68(7): 343-346.
11 Watanabe K, Tsuchiya H, Sakurakichi K, et al. Double-level correc-tion with the Taylor Spatial Frame for shepherd’s crook deformity in J Orthop Sci, 2007, 12(4): 390-394.
12 Dunstan E, Tilley S, Briggs TW, et al. A customised replacement for polyostotic brous dysplasia of the upper femur. a 51-year follow-up.J Bone Joint Surg (Br), 2005, 87(1): 114-115.
13. Zhu X, Dong Y, Yang QC. Clinical features and treatment of large segmental fibrous dysplasia of long bones of the extremities. International Journal of Orthopaedics 2011; 31(4): 245-247
14. Zhang X.D., Hu Y.P., Yu Z.S., et al. Clinical analysis of abnormal bone fiber proliferation disorder. Chinese and Foreign Medical 2010;28:11-12
15. Zhang LH ,XU Shaoting ,ZHU Bing ,et al. Surgical treatment of abnormal proliferation of bone fibers in the extremities [J]. Chinese Journal of Orthopaedic Surgery,2002,10(11):1054-1056.