[Abstract] OBJECTIVE: To summarize the method and efficacy of internal fixation of patellar ring in the treatment of comminuted patella fracture. Methods: From April 2007 to April 2010, 27 patients with comminuted patella fractures were admitted, 23 males and 4 females, aged 23-67 years old, average 44 years old, with duration of disease from 2 h to 12 d. All patients underwent fracture dissection and were treated with patellar ring internal fixation developed by Tianjin Weimann Biomaterials Co. Results: The incision healed at stage I after surgery without complications. 20 cases were followed up for 5-14 months, and all bones healed at an average of 5 months after surgery, with good functional recovery of the knee joint. Conclusion: The treatment of patellar comminuted fracture with patellar ring internal fixation is a better method for treating patellar comminuted fracture, with firm fixation and good functional recovery after surgery. Wang Weiguo, Department of Orthopaedic Traumatology, Jinan Military Region General Hospital
Keywords: patellar fracture, patellar ring, internal fixation
There are many surgical treatment methods for patellar fracture, including tension band fixation, patellar claw fixation, silk suture fixation, wire load fixation, etc. The authors treated 27 cases of comminuted patella fractures with surgical internal fixation of patellar ring developed by Tianjin Weimann Biomaterials Co., Ltd. from April 2007 to April 2010, and abandoned the previous postoperative external fixation of plaster, and achieved satisfactory results, which are reported below.
1 Clinical data
1.1 General data
There were 27 cases in this group, 23 males and 4 females, age 23-67 years old, average age 44 years old; 10 cases on the left side and 17 cases on the right side. Cause of injury: 19 cases of fall injury and 8 cases of car accident injury. The time from injury to surgery was 2 h to 12 d. All cases were comminuted fractures, including 7 cases of open fractures. All cases were treated surgically.
1.2 Surgical method
The surgery was performed under continuous epidural anesthesia with a tourniquet. The anterior patellar transverse arc incision was selected with the convex side down, the skin and subcutaneous tissues were incised, and the flap was turned upward to fully expose the fracture blocks of the patella, remove the blood clots in the joint cavity and on the fracture blocks, and return the turned-in periosteum and prepatellar tissues to the patellar surface. In the 10° bent knee position, the patellar fracture was repositioned, held in place with a scarf clamp, and the patellar articular surface was flattened by touching the patellar joint through the dilated fissure with the fingers, and then two to three kerf pins were inserted to temporarily penetrate and fix the fracture blocks. The scarf clamp was removed, the patellar ring was placed on the surface of the patella, and two positioning pins were inserted into the positioning holes for fixation. Then insert 2 fixation hooks in different directions along the corresponding holes above and below the patellar ring, with the tips of the hooks piercing the patellar tendon membrane and patellar ligament and hooking directly on the upper and lower edges of the patella, confirming that the hooks are firmly placed, holding the upper and lower hooks with a hook presser for centripetal pressure, and then using a hook splitter to separate the inner part of the hooks and fix them firmly. The number of hooks and the position of the holes can be selected according to the intraoperative situation, generally 4 to 8 hooks are needed. When all fixation hooks are placed, pressure is again applied centripetally, respectively, so that the entire fractured patella is ringed and fixed. The incision was closed with layer-by-layer sutures. Functional exercises in bed were started 3 days after surgery, and partial weight-bearing walking was performed about 10 weeks after surgery according to the healing of the fracture.
2 Results
In this group, 20 cases were followed up from 5 to 14 months after surgery, and all the bones healed at an average of 5 months after surgery. X-ray showed good patellofemoral joint alignment and good recovery of knee flexion and extension function. According to the efficacy assessment criteria of Lu Yupu et al, there were 21 excellent cases, 6 good cases and no poor cases in this group.
3 Discussion
3.1 Advantages of patellar ring fixation
The patellar ring placed in front of the patella fixes the anterior patellar compression, which produces balanced compression due to muscle tension and patellar resistance. In the application of tension band fixation Kirschner’s pin is prone to tenderness and even infection at the end of the pin. Wire fixation is prone to wire loosening or fracture and fracture displacement; in addition, wire can affect tissue blood flow. The patellar claw has been found to be a poor fixation for irregular comminuted patella fractures. The patellar ring can effectively fix the patella, while the contact surface of the ring and hook with the soft tissue is smooth, with little friction, avoiding the infection of touching the tail of the kerfing needle; the ring and patella are fixed as one, without relative movement, so that the metal breaks due to fatigue during the movement, and the blockage of blood flow to the intermediate tissues by the wire is avoided. The use of the patellar ring can achieve a strong and reliable fixation effect in the management of comminuted patellar fractures, and the previous postoperative external fixation in a cast can be abandoned, and early functional training can be performed to achieve satisfactory surgical results.
3.2 Early functional training
Early functional training is an important part of postoperative treatment of patellar fractures. So far, most of the patellar fractures have been externally fixed in plaster for a certain period of time after internal fixation surgery. In this group of cases, while emphasizing the strong and stable internal fixation, early functional training after surgery was placed in an important position in the treatment of the fracture. The purpose of strong internal fixation is to restore the maximum function of the affected limb, and postoperative joint stiffness, muscle atrophy, and traumatic arthritis are common complications of patella fracture. Only early postoperative functional training can effectively avoid complications. In this group of cases, postoperative swelling was effectively treated with an intravenous pump, and passive plus active training was performed with the help of a CPM machine. The functional training can further enhance the venous return of the affected limb, reduce pain and swelling, and effectively avoid traumatic osteoarthritis; early activity gives pressure to the joint, which is conducive to cartilage nutrition and accelerates the recovery of joint function, achieving satisfactory results.