The clinical treatment of old femoral neck fractures in young adults is difficult. Due to the age factor, joint replacement surgery is obviously inappropriate, and methods such as simple incisional reduction and hollow screw internal fixation are not suitable for the treatment of this disease. How to promote fracture healing, delay the development of femoral head necrosis, and restore the function of the hip joint has become the fundamental part of the treatment of this disease.
Since 1998, based on the treatment of ischemic necrosis of the femoral head with sutured iliac bone flap, we have been applying the combination of multiple nail internal fixation with sutured iliac bone flap and lateral vascular bundle implantation or simultaneous free iliac bone plate to reconstruct the femoral neck in 87 cases of young adults with old fractures of the femoral neck, with satisfactory long-term results.
I. Clinical data
A total of 87 cases of old femoral neck fractures in young adults were admitted from March 1998 to June 2008, of which 64 cases had complete follow-up data. There were 49 male cases and 15 female cases, 34 cases on the right side and 30 cases on the left side.
There were 26 cases under 30 years of age, 20 cases between 31 and 40 years of age, 11 cases between 41 and 50 years of age, and 7 cases over 51 years of age; the youngest was 16 years old, the oldest was 56 years old, and the average age was 33.1 years. Cause of injury: 15 cases of fall from height injury and 49 cases of car accident injury.
The original treatment methods: 12 cases of simple traction, 14 cases of percutaneous closed reduction hollow compression nail fixation, 10 cases of double-headed compression nail, 2 cases of misdiagnosis (1 case to 34 days of fracture confirmed, 1 case to 45 days of fracture confirmed), 2 cases of three-winged nail fixation, 13 cases of Stiletto pin fixation, 7 cases of scalene nail fixation, and 4 cases of easy fracture nail fixation.
The time between injury and this operation ranged from 34 days to 24 months, with an average of 8.7 months. garden fracture typing: 25 cases of type III and 39 cases of type IV.
Physical examination: 23 cases had a shortened limb of less than 2 cm, 14 cases had a shortened limb of 2-3 cm, and 27 cases had a shortened limb of more than 3 cm. X-ray examination showed widespread osteoporosis of the femoral ridge, no obvious bone scab growth at the fracture end, 15 cases had different degrees of bone resorption at the fracture end, and 8 cases had focal sclerosis and cystic changes of the femoral head.
II. Treatment methods
If the femoral neck fracture does not heal and the shortening of the affected limb is more than 3 cm, supracondylar bone traction is performed, and the operation is performed after the fracture end can be seen on the review X-ray and the neck stem angle is basically restored. During surgery, the patient is placed supine, the affected hip is elevated with a thin pillow, continuous epidural anesthesia or general anesthesia, and the surgical incision is made through the Smith-Perteson approach.
(a) In the case of old fracture of the femoral neck that simply does not heal, the S-P incision of the affected hip is taken to be about 20 cm long, and the skin and superficial deep fascia are incised in turn. The lateral femoral cutaneous nerve is found at about 2.5 cm below the anterior superior iliac spine, which is free distally and proximally and held medially to protect it.
A moderately sized iliac bone flap with a sutures muscle tip was excised and wrapped in wet gauze for backup, and blunt dissection was performed along the sutures muscle and broad fascial tensor fasciae muscle gap to separate the ascending, transverse, and descending branches of the lateral femoral artery, ligating its genital and terminal branches for backup.
The hip capsule was exposed by blunt dissection along the rectus femoris and gluteus medius muscle gaps, and a “T”-shaped incision was made to remove the anterior part of the capsule, expose the fracture end of the femoral neck and the head and neck, clean the clot and embedded soft tissues at the fracture end, and reset anatomically under direct vision, with C-arm/G-arm surveillance at 1 cm, 3 cm, and 4 cm below the apex of the greater trochanter, respectively. Three guide pins were drilled parallel to the head and neck direction under C-arm/G-arm surveillance.
The hollow compression nail was fixed (in the early stage of this procedure, bone round pins and scalene nails were used for fixation), and after the hollow nail was well positioned and the fracture end was satisfactorily aligned on positive axial fluoroscopy, a suitable bone groove was cut in front of the fracture end, the sutures were trimmed to fit the iliac flap, the bone flap was embedded in the bone groove and driven into the femoral head, the cancellous bone of the iliac bone was trimmed into suitable bone particles and pressed and filled around the bone flap, and one absorbable screw was inserted vertically into the femoral neck. The bone flap is fixed in the axis of the femoral neck.
Two (V-shaped) or one bone tunnel was drilled from the craniocervical junction to the upper part of the head, and the vascular bundle of the terminal branch of the external rotor femoral artery was implanted under the cartilage surface with a homemade vascular spatula. After moving the hip joint under direct vision and seeing that the bone flap is secure and the vascular bundle of the external rotor femoral artery is free of traction, tension and distortion, the incision is flushed again to stop bleeding completely, and after counting the gauze instruments, a negative pressure drainage tube is placed, sutured layer by layer and dressed with sterile dressing.
(B) In the case of old fracture of the femoral neck with significant shortening of the affected limb by resorption, on the basis of the above operation, another free iliac bone flap is taken, and according to the preoperative X-ray measurement and the length of femoral neck shortening seen during the operation and the angle of hip inversion, it is trimmed into a round wedge-shaped bone plate suitable for the cross-section of the femoral neck, the surface periosteum and cortical layer are occluded, and the femoral neck is filled with 3 to 10 small holes drilled with a 1.5 mm kerf needle. The fracture end was drilled with 3 to 10 small holes using a 5mm kerf needle to fill the femoral neck, correct the shortened deformity of the femoral neck, anatomically reset under direct vision, and fixed with a hollow compression nail.
The quadriceps contraction exercise or CPM machine assisted exercise can be performed in bed on the second day after surgery, and after 10-24 weeks, the patient will be able to walk in bed with double crutches without weight, and X-ray examination will be performed once a month for 3 months after surgery, and every 3 months thereafter. In accordance with the three stages of TCM injury medicine, homemade San Qi bone marrow was taken within 2 weeks after surgery to activate blood circulation and eliminate blood stasis, reduce swelling and pain; after 2 weeks, homemade special bone marrow and femoral head necrosis healing were taken to promote fracture healing and reduce femoral head necrosis.
Results
Sixty-four cases were followed up for 12 to 96 months, with an average of 37 months. 62 cases healed, with clinical healing time of 3 to 10 months, with an average of 7.5 months. The clinical healing time of 15 patients with femoral neck resorption was 6 to 10 months after surgery, which was 3 to 4 months longer than that of those without significant femoral neck resorption.
In two cases, the fracture end of the femoral neck was displaced upward and the internal fixation was loosened due to premature weight-bearing after surgery, and joint replacement surgery was eventually performed.
In 11 cases, mixed high and low densities were found in the femoral head at the last review, but the acetabulum and femoral head joint surface were still smooth, and the patients had no obvious pain and functional limitation; 10 cases had femoral neck shortening, femoral head collapse and deformation, joint space narrowing, and obvious functional limitation (7 of them were over 40 years old). 12 cases with femoral neck bone resorption recovered normal femoral neck length after surgery. The efficacy of all cases was evaluated at the last follow-up according to the Harris scale, with a mean score of 85.2.
DISCUSSION
Despite the current developments and advances in the treatment of femoral neck fractures, the rate of nonunion of fresh femoral neck fractures remains high. In addition to the particular blood supply to the femoral head and the early damage caused by fracture displacement, the difficulty of maintaining fracture end stability by traction alone, inaccurate repositioning, or inadequate internal fixation to resist rotation of the fracture end, results in fracture end instability.
Continued aggravation of local blood flow destruction also significantly increases the incidence of non-union of the femoral neck fracture and neck resorption with head necrosis. In some cases, misdiagnosis due to lack of obvious post-injury symptoms or ambiguous radiographs and limited diagnosing physicians is another cause of failure to treat this disease that should not be overlooked.
For young and middle-aged patients, many scholars have returned to the study of preserving their own hip joint surgery because the artificial joint has to face the problem of prosthesis life and revision.
According to our group’s experience, this procedure is suitable for those who are under 50 years of age, whose femoral head has not yet been necrotic or below Ficat stage IIIA, and who have no other obvious contraindications to surgery. During the treatment, attention should be paid to.
(1) Adequate preoperative traction is performed to correct the overlapping displacement of the fracture end in order to facilitate accurate assessment of the degree of femoral neck shortening and resorption. Depending on the patient’s physical condition and the degree of shortening of the fracture end, the maximum traction weight can be up to 15 KG and the traction time can be up to 1 month.
(2) Intraoperative separation of the lateral vascular bundle of the rotated femur should free as many and as fine end vessels as possible to improve the chances of re-growth of the vascular bundle.
(3) When trimming the iliac bone plate to reconstruct the shortened femoral neck, care should be taken to remove the periosteum and cortical bone on the surface of the plate, and 3 to 10 small holes should be drilled with a kerfing needle after trimming; the bone flap implantation is done by a combination of compression bone grafting and granular bone grafting, which is clinically observed to shorten the trabecular crawling time and facilitate fracture healing.
(4) Internal fixation is a difficult part of this procedure. The two assistants should work closely to maintain the repositioning, and the number of internal fixation nails should be decided according to the stability of the fracture end after repositioning.
(5) Postoperatively, wear “Ding” shoes and maintain the lower limb in traction until 10-24 weeks, and decide the time to get out of bed depending on the healing of the fracture, and do not walk with weight by holding the crutches in the early stage to avoid affecting the stability of the fracture end.
(6) According to our experience, the femur is an important external rotator of the hip joint, and cutting the bone flap with the femur has a greater impact on the function of the hip joint; the blood supply of the bone flap is affected by the high incidence of vascular compression, distortion, spasm and blockage of the iliac bone flap with the vascularity alone. The blood supply of sutures muscle is segmental, with seven arteries entering the muscle belly from different planes, and the sutures muscle has a long tip, which is convenient to transfer and easy to take from the superficial donor area. The transplanted bone flap not only has a good blood supply, but also has a periosteum, which has both a certain support and osteogenic effect.
There are many internal fixation methods for femoral neck fractures reported in the literature, such as triple-wing nailing, multiple Stiffen pins, and hollow nailing. Although the three-wing nail can eliminate the shear force of the fracture end and prevent the rotation of the femoral head, the intraoperative insertion of the fracture end cannot maintain or have a lasting compression effect after surgery; moreover, the nail body is thick and increases the instantaneous pressure of the hip joint when it is driven in, which causes greater damage to the residual blood supply of the femoral head.
The multi-staple internal fixation is simple and flexible, with little damage to the femoral head and a reasonable biomechanical layout, but loosening and slipping of the nail are the most frequent complications. These two fixation methods are more difficult to achieve stable fixation in old fractures of the femoral neck, especially in cases with bone resorption at the fracture end, and inevitably prolong bed rest and increase the difficulty of postoperative care.
In the early stage of this procedure, we used multiple Stiffener pins and scalene nails for fixation. Although scalene nails have better anti-slip properties than Stiffener pins, scalene nails are difficult to remove and easy to break, and in one case, the broken nail could not be removed and had to be left in the patient’s body, but there was no discomfort in the patient during long-term observation.
The hollow nail has the characteristics of anti-rotation and reduction of shear stress, which can effectively avoid the deficiencies of Searle’s pin and scalene nail; especially the hollow nail has cancellous bone thread at the front end, which is firmly fixed and is superior to old fractures with osteoporosis.
Some scholars are concerned that the space for internal fixation is too small after grooving in front of the femoral neck, but for cases with a larger diameter of the femoral neck and poor stability of the fracture end after repositioning, it is not a bad idea to increase the number of fixation nails according to the specific situation, in order to achieve stability of the fracture end.
In one case, the fracture did not heal 22 months after surgery, and the femoral neck was shortened by 4 cm. After reconstruction of the femoral neck, it was found that 3 nails were difficult to fix firmly, and the osteoporosis in the ridge area was obvious, so one more nail was added and a spacer was used at the end of the nail. At 20 months after surgery, the CT showed that the fracture end healed well, the femoral head still did not show any obvious signs of necrosis, and the functional Harris score of the affected hip was 92.
According to experience, the normal bone repair response of the femoral head after femoral neck fracture is different from that of femoral head necrosis. The difference mainly lies in the CT performance. Both of them can be seen as mixed high and low densities, but the former mostly shows extensive, punctiform changes with a ring-shaped very high-density shadow around it, with clear boundaries, and generally does not change significantly within several years, and patients often have no obvious clinical discomfort; the latter mostly shows a piecewise mixed high and low density shadow, often without clear boundaries, and recent imaging changes are large, and patients mostly have pain, acidity and other symptoms clinically. In the second case cited in this paper, the patient had no obvious discomfort for 8 years of follow-up, the femoral head shape was always intact, and there were no major changes in the trabecular structure of the femoral head as seen by CT.
With the accumulation of surgical experience, we will further improve this surgical method and strive for new improvements in enhancing the stability of the fracture end, accelerating fracture healing and early postoperative functional exercise. In all cases, it is still appropriate to continue observation, and it is difficult to make a precise judgment about the development of the disease in the more distant future.